KIEV, Aug 28 (Reuters) - Ukraine's president said on Thursday that Russian troops had entered his country in support of pro-Moscow rebels who captured a key coastal town, sharply escalating a five-month-old separatist war.
President Petro Poroshenko told a meeting of security chiefs that the situation was "extraordinarily difficult ... but controllable" after Russian-backed rebels seized the town of Novoazovsk in the southeast of the former Soviet republic.
Earlier Poroshenko said he had canceled a visit to Turkey because of the "rapidly deteriorating situation" in the eastern Donetsk region, "as Russian troops have actually been brought into Ukraine".
Russia's defense ministry again denied the presence of its soldiers in Ukraine, using language redolent of the Cold War.
"We have noticed the launch of this informational 'canard' and are obliged to disappoint its overseas authors and their few apologists in Russia," a ministry official, General-Major Igor Konashenkov, told Interfax news agency. "The information contained in this material bears no relation to reality."
But skeptical Western governments appeared to be running out of patience with Moscow's denials.
Referring to talks that Putin held with Poroshenko just two days ago, British Prime Minister David Cameron said: "It is simply not enough to engage in talks in Minsk, while Russian tanks continue to roll over the border into Ukraine. Such activity must cease immediately."
Poland's foreign minister said Russian "aggression" had created the most serious security crisis in Europe for decades. A top NATO official said Russia had significantly escalated its "military interference" in Ukraine in the past two weeks.
"We assess well over 1,000 Russian troops are now operating inside Ukraine," said Dutch Brigadier-General Nico Tak, head of NATO's crisis management center. "They are supporting separatists (and) fighting with them."
Two human rights advisers to Putin said that more than 100 Russian troops had died in Ukraine in a single attack on Aug. 13, and one of them said she considered Russia's actions an invasion.
Global stock markets fell on news of the worsening crisis, which has prompted the United States and European Union to impose sanctions on Moscow and led both Russia and NATO to step up military exercises, creating the tensest East-West standoff since the Soviet Union collapsed in 1991.
The United States is considering a number of options in response to Russian involvement in eastern Ukraine and believes sanctions are the "most effective tool", U.S. State Department spokeswoman Jen Psaki said.
German Chancellor Angela Merkel said an EU summit on Sunday would discuss the possibility of further sanctions.
Rebel advances this week have opened a new front in the conflict just as Ukraine's army appeared to have gained the upper hand, virtually encircling the separatists in their main strongholds of Donetsk and Luhansk.
A Ukrainian presidential spokesman said on Twitter that Poroshenko's central message to his security chiefs was: "We are capable of defending ourselves. The main thing is not to panic."
The defense and security council said it was re-introducing compulsory military service from this autumn, but conscripts would not serve in the conflict zone.
Earlier, the council said Novoazovsk, on the Azov Sea, and other parts of southeast Ukraine had fallen under the control of Russian forces, and a counter-offensive by Russian troops and separatist units was continuing.
It said Ukrainian government forces had withdrawn from Novoazovsk "to save their lives" and were now reinforcing defenses in the port of Mariupol further west, which a rebel leader said was the separatists' next objective.
"Today we reached the Sea of Azov, the shore, and the process of liberating our land, which is temporarily occupied by the Ukrainian authorities, will keep going further and further,"
Alexander Zakharchenko, prime minister of the self-proclaimed Donetsk People's Republic, told Reuters in an interview.
He said there were about 3,000 Russian volunteers serving in the rebel ranks.
Ukrainian Prime Minister Arseny Yatseniuk appealed to the United States, EU and G7 countries "to freeze Russian assets and finances until Russia withdraws armed forces, equipment and agents".
Anton Gerashchenko, an adviser to Ukrainian Interior Minister Arsen Avakov, said on Facebook: "The invasion of Putin's regular Russian army of Ukraine is now an established fact!"
Despite Moscow's denials, a member of Putin's advisory council on human rights, Ella Polyakova, told Reuters she believed Russia was carrying out an invasion of Ukraine.
"When masses of people, under commanders' orders, on tanks, APCs and with the use of heavy weapons, (are) on the territory of another country, cross the border, I consider this an invasion," she said.
Polyakova and Sergei Krivenko - another member of the council which has no legal powers and an uneasy relationship with the Kremlin - said their information on the Aug. 13 attack was based on accounts by eyewitnesses and relatives of the dead.
They said the troops had been in trucks filled with ammunition. "A column of Russian soldiers was attacked by Grad rockets and more than 100 people died. It all happened in the city of Snizhnye in Donetsk province," Krivenko told Reuters.
In southern Russia on Thursday, a Reuters reporter saw a column of armored vehicles and dust-covered troops, one of them with an injured face, about 3 km (2 miles) from the border with the part of Ukraine that Kiev says is occupied by Russian troops.
The column was driving east, away from the border, across open countryside near the village of Krasnodarovka, in Russia's Rostov region.
None of the men or vehicles had standard military identification marks, but the reporter saw a Mi-8 helicopter with a red star insignia -- consistent with Russian military markings -- land next to a nearby military first-aid tent.
Asked if he was with the Russian military, a man near the tent in camouflage fatigues but without any identifying insignia, said only: "We are patriots."
The U.S. ambassador to Kiev, Geoffrey Pyatt, tweeted: "Russian supplied tanks, armored vehicles, artillery and multiple rocket launchers have been insufficient to defeat Ukraine' armed forces. So now an increasing number of Russian troops are intervening directly in fighting on Ukrainian territory.
"Russia has also sent its newest air defense systems including the SA-22 into eastern Ukraine & is now directly involved in the fighting," he said.
Fighting in the east erupted in April, a month after Russia annexed Ukraine's Crimean peninsula in response to the toppling of a pro-Moscow president in Kiev.
A United Nations report this week said more than 2,200 people have been killed, not including the 298 who died when a Malaysian airliner was shot down over rebel-held territory in July. (Additional reporting by Maria Tsvetkova, Anton Zverev, Gabriela Baczynska, Vladimir Soldatkin and Thomas Grove, Adrian Croft, Lina Kushch, Andreas Rinke and Alessandra Prentice; Writing by Mark Trevelyan; Editing by Will Waterman and David Stamp)
09/06/2014 6:08 PM EDT
Factory Ablaze After Artillery Fire Near Mariupol
Prolonged artillery fire was heard late on Saturday to the east of the port of Mariupol in eastern Ukraine, a Reuters reporter said, in what may be the first significant violation of a ceasefire declared little more than 24 hours earlier.
The reporter saw an industrial facility, a truck and a gas station ablaze in an area within the limits of Mariupol, a city of 500,000 people on the Sea of Azov near the Russian border.
The area had seen fierce fighting between Ukrainian government forces and pro-Russian separatists before the ceasefire took effect on Friday evening. It had been quiet since then until the artillery fire began late on Saturday.
"There has been an artillery attack. We received a number of impacts, we have no information about casualties," a Ukrainian officer told Reuters at the scene.
09/06/2014 6:03 PM EDT
Ukraine Battalion: Reports Of Civilian Casualties In Shelling
09/06/2014 6:00 PM EDT
#RussiaViolatedCeasefire Trends On Twitter
Twitter users are using the hashtag #RussiaViolatedCeasefire to blame Moscow for renewed violence in east Ukraine.
Hashtag #russiaviolatedceasefire is now showing up as a suggestion. Good work, fellow Ukrainians— неХуёвый Portland (@the_boris) September 6, 2014
Meanwhile, Lithuanian Ambassador to Sweden Eitvydas Bajarunas used the hashtag for call for more information, as rockets and shelling were reported in the Ukrainian port city of Mariupol.
09/06/2014 5:43 PM EDT
Rockets Fired In Ukraine Amid Ceasefire
Witnesses in the Ukrainian port city of Mariupol are reporting sustained explosions outside the city and a volunteer battalion of Ukrainian fighters says Grad rockets are being fired at its positions.
The reports Saturday night come little more than a day after Ukraine and Russian-backed separatist rebels signed a cease-fire after more than four months of fighting in the country's east.
The cease-fire had appeared to largely been holding during much of the day.
But late Saturday, witnesses in Mariupol told The Associated Press by telephone that heavy explosions were coming from the city's eastern outskirts, where Ukrainian troops retain defensive lines against the rebels.
The volunteer Azov Battalion said on Facebook that their positions were hit by Grad rockets, but did not give details.
09/06/2014 4:49 PM EDT
Reports Of Shelling In Mariupol
BBC journalists Fergal Keane and Will Vernon in Ukraine's Mariupol say that shelling of the port city has resumed.
#Ukraine shelling started at approx 2235 local and is continuing— Fergal Keane (@fergalkeane47) September 6, 2014
#Ukraine On roof of hotel and can see flashes from explosions and hear powerful detonations.— Fergal Keane (@fergalkeane47) September 6, 2014
09/06/2014 12:21 PM EDT
ICRC Says Aid Trucks Forced Back By Shelling
The International Committee of the Red Cross said its aid trucks were forced to turn back on Saturday morning due to shelling in east Ukraine.
09/06/2014 10:59 AM EDT
Putin, Poroshenko Agree Cease-Fire Holding
Russian President Vladimir Putin and Ukraine's President Petro Poroshenko agreed on Saturday in a telephone call that a ceasefire in eastern Ukraine was generally holding but said further steps were needed to make it more durable.
The ceasefire between Ukrainian government forces and pro-Russian separatists took effect on Friday evening, part of a wider peace plan aimed at ending five months of fighting in eastern Ukraine.
"(The two leaders) also stressed the need for the maximum involvement of the Organisation for Security and Cooperation in Europe (OSCE) in monitoring the situation ... and for cooperation in providing Ukrainian and international humanitarian help," Poroshenko's office said in a statement.
09/06/2014 10:58 AM EDT
Rebel Leader: Prisoner Exchange To Take Place Saturday
A separatist leader said that the rebels and Ukrainian government will begin the exchange of prisoners of war, part of the peace roadmap, later on Saturday, Reuters reports. Meanwhile, Kiev said the details of the exchange were still being worked out.
09/05/2014 12:38 PM EDT
Peace Deal Outlined
New York Times Moscow bureau chief Neil MacFarquhar outlines the different aspects of the Ukrainian peace deal.
The Ukrainian National Information Agency released a list of the 14 points included in the cease-fire plan. #Ukraine— Neil MacFarquhar (@NeilMacFarquhar) September 5, 2014
2 some focused on cease-fire itself, some on practical steps to get the government functioning and some on Donbas political future. #Ukraine— Neil MacFarquhar (@NeilMacFarquhar) September 5, 2014
3 The agreement followed almost verbatim a cease-fire proposal first put out by Mr. Poroshenko in June.— Neil MacFarquhar (@NeilMacFarquhar) September 5, 2014
4 14 points include amnesty for all those who disarm and who did not commit serious crimes, as well as the release of all hostages. #Ukraine— Neil MacFarquhar (@NeilMacFarquhar) September 5, 2014
5 Militias will be disbanded, and a 10-kilometer buffer zone established along Russian-Ukrainian border. Area subject to joint patrols— Neil MacFarquhar (@NeilMacFarquhar) September 5, 2014
6 Separatists agreed to leave administrative buildings they control and broadcasts from Ukraine to resume on TV #Ukraine— Neil MacFarquhar (@NeilMacFarquhar) September 5, 2014
7 On future, the agreement said power would be decentralized and the Russian language protected. Region consulted on selection of governor— Neil MacFarquhar (@NeilMacFarquhar) September 5, 2014
8. Early elections and jobs....No mention of a chicken in every pot. #Ukraine— Neil MacFarquhar (@NeilMacFarquhar) September 5, 2014
09/05/2014 12:18 PM EDT
Obama: Hopeful But Skeptical
U.S. President Barack Obama said he was hopeful but skeptical about a ceasefire agreed in Ukraine on Friday and urged European allies to agree on new sanctions against Russia that could be suspended if the peace plan holds.
He also said he was leaving a two-day NATO summit in Wales confident that U.S. allies were prepared to join a broad coalition to take action to degrade and ultimately destroy Islamic State militants in Iraq.
"We also sent a strong message to Russia that actions have consequences. Today the United States and Europe are finalizing measures to deepen and broaden our sanctions across Russia's financial, energy and defense sectors," Obama told a news conference.
NATO had made clear it would defend every ally, and that it supported Ukraine's sovereignty against what he called Russian aggression, he said.
"With respect to the ceasefire agreement, obviously we are hopeful but based on past experience also skeptical that in fact the separatists will follow through and the Russians will stop violating Ukraine's sovereignty and territorial integrity. So it has to be tested," the president said.