By Michelle Nichols
UNITED NATIONS, July 25 (Reuters) - U.N. Security Council members blamed each other for rising violence in Syria on Wednesday, with Western states pledging to also seek an end to the 16-month conflict outside the world body as Russia warned of "likely catastrophic consequences" with that approach.
Russia, an ally of Syria, and China have repeatedly blocked Western-backed Security Council attempts to increase pressure on Syrian President Bashar al-Assad to end the violence sparked by a government crackdown on pro-democracy protesters.
"The Syrian people will pay the price for this failure (to act)," Germany's U.N. Ambassador Peter Wittig told a U.N. Security Council debate on the Middle East on Wednesday.
With Russia and China pitted against their permanent veto-wielding counterparts the United States, Britain and France, the 15-member council is deadlocked and Washington has said it will seek ways to tackle the crisis in Syria outside the world body.
"Such a policy has been followed by Washington and a number of other capitals since the beginning of the crisis in Syria and this has significantly exacerbated it," Russia's U.N. Ambassador Vitaly Churkin told the council debate on the Middle East.
Churkin said Washington would "bear the responsibility for the likely catastrophic consequences of such steps."
"A situation where the opposition, a significant part of which does not wish to hear of dialogue, is told that it will be further helped - this contributes and leads to an escalation of confrontation," Churkin said.
The United States has said it will turn to alternatives such as the "Friends of Syria" grouping of allied countries to find ways to pressure Assad after the Security Council's failure to agree on consequences for Syria's violations of a peace plan brokered by the United Nations and Arab League envoy Kofi Annan.
"Since this Council failed to shoulder its responsibilities, the United States will continue to work with the (Friends of Syria)," Deputy U.S. Ambassador to the United Nations Jeffrey DeLaurentis said on Wednesday.
He said Washington would work to increase pressure on the Syrian government, support the Syrian opposition, organize aid, and help prepare for a Syrian-led, democratic transition.
Russia and China - who support each other on the council to protect their respective allies from interference - on Thursday vetoed a resolution that threatened Syrian authorities with sanctions if they did not stop using heavy weapons in towns because Russia said the threats by the council were one-sided.
"They are prepared to deny the council the ability to influence the situation for the better," Britain's U.N. Ambassador Mark Lyall Grant told the Security Council debate.
"The consequences are clear: further violence and bloodshed and a deteriorating situation that is now spilling over the borders," he said, referring to incursions by Syrian troops into Lebanon and the Israeli-occupied Golan Heights.
Assad's forces have killed more than 15,000 people since a crackdown on pro-democracy protesters began in March 2011, some Western leaders say. Damascus says rebels have killed several thousand of its security forces.
The Syrian army turned its forces on Aleppo on Wednesday, ordering an armored column to advance on the country's second largest city and pounding rebels there with artillery and attack helicopters, opposition activists said.
"The impotence to which the council has been confined by the Russian and Chinese vetoes does not leave the council without recourse," French U.N. Ambassador Gerard Araud told the council.
"We will continue our support to the Syrian people and the advent of a democratic transition," said Araud, adding that France would continue to support the opposition in Syria. (Reporting by Michelle Nichols; editing by Todd Eastham)