ANKARA, Turkey — Turkey's prime minister said Tuesday his nation's navy will step up its surveillance of the eastern Mediterranean Sea – a move that could potentially lead to confrontation with Israel – and warned of more sanctions against Israel as relations between the former allies deteriorated further.
Turkey has already suspended its vast military ties with Israel, said it is expelling top Israeli diplomats and pledged to lobby other nations in support of the Palestinians' statehood bid after Israel refused to apologize for last year's raid on a Gaza-bound flotilla that killed nine Turkish pro-Palestinian activists.
The sudden measures mark a stunning reversal for the two nations, who were once each other's top military trading partners and used to regularly train together on each other's soil.
Israel has expressed regret for the loss of lives aboard the flotilla and said Tuesday it was time for the two countries to restore their former close ties.
"Israel and Turkey are the two strongest nations in the Middle East and in many respects, the most important," Israeli Defense Minister Ehud Barak said before Turkish Prime Minister Recep Tayyip Erdogan's latest threats.
"We have disputes, and even in the case of disputes, it's very important that the two sides use their brains and not act from the gut. It would be best for all involved and in the interest of regional stability to patch things up," Barak said.
A United Nations report released last week said Israel's naval blockade of Gaza was a "legitimate security measure," but also called the raid on the flotilla that tried to break the blockade "excessive and unreasonable." It also said Turkey and the flotilla organizers contributed to the bloodshed.
Israel has accepted the U.N. report, albeit with reservations. Turkey has rejected it.
Erdogan has said the "report does not mean anything for us," and announced the suspension of some trade and military relations. Turkey has not imposed a trade embargo on Israel but suspended ongoing defense projects and purchases from Israeli defense firms.
The breakdown in relations has hurt a key alliance for Israel, which has considered Turkey its strongest ally in the Muslim world.
It is unclear what impact the Turkish decision to scale back economic ties will have. Israeli defense officials said there have not been any new agreements since 2008, just before relations began to deteriorate.
The officials, speaking on condition of anonymity because they were discussing a sensitive diplomatic matter, said Israel was committed to the existing deals and would continue to provide military gear to Turkey despite the latest crisis.
At its height in the late 1990s, Israel exported to Turkey billions of dollars worth of tanks, unmanned aircraft and military technology. Turkey is also a top business partner and tourist destination for Israelis.
Israeli officials noted paradoxically that despite the tension in recent years, 2011 has been a record year thus far in overall trade.
Relations began deteriorating as a result of Israel's campaign against Gaza rocket launchers in early 2009, in which about 1,400 Palestinians were killed, and worsened dramatically after the May 2010 raid on the Mavi Marmara vessel.
Turkey's latest moves were prompted after it was disappointed by the U.N. report's failure to criticize Israel more strongly and force it to apologize.
Erdogan did not detail what the next round of sanctions against Israel would include. But he vowed to ensure "freedom of navigation" in the eastern Mediterranean by using Turkey's naval bases in the ports of Iskenderun and Aksaz to "keep the area under constant surveillance."
"Of course, our ships will show themselves quite often from now on. We will see it very often," Erdogan said.
Israel's navy closely protects its coastline and enforces the Gaza blockade, but does not have a major naval presence in the eastern Mediterranean.
Turkey's main opposition party warned last week that military moves could lead to confrontation between Turkish and Israeli forces.
"The probability that (Turkey's ruling) party has carried Turkey to the brink of a hot conflict is saddening and unacceptable," said Faruk Logoglu, a deputy chairman of the opposition Republican People's Party.
Alon Liel, a former Israeli ambassador to Turkey, said a conflict on the seas was a possibility.
"I don't think they would dare to penetrate Israeli waters," he told reporters in Jerusalem. But he said Turkey may try to disrupt future Israeli gas exports to Cyprus and he warned of a new Turkish-Egyptian alliance that could isolate Israel in the Mediterranean.
Israel's opposition leader, Tzipi Livni, on Tuesday urged the countries to "put aside all the emotions and to enter the room and to discuss what are the next best steps in order to stop this crisis."
In Washington, the Obama administration was scrambling to keep ties between the two U.S. allies from deteriorating further.
Senior American diplomats, including Secretary of State Hillary Rodham Clinton, are working with both countries to "de-escalate" and "defuse" the crisis, the State Department said Tuesday. Turkey is a key NATO ally of the United States, while Israel is America's top ally in the Middle East.
"We have over many months tried to work with our ally Turkey and our ally Israel to strengthen and improve their bilateral relationship," State Department spokeswoman Victoria Nuland said. "We still believe that getting back to a good partnership between them is in each of their interests, and we will continue to work for that goal with both of them. But we are concerned about the state of the relationship today."
Clinton discussed the matter at length with Turkish Foreign Minister Ahmet Davutoglu last Thursday in Paris, while two top Mideast specialists, David Hale and Dennis Ross, raised the issue with Israeli officials on Tuesday.
Israeli military officials said they doubted the crisis would devolve into violence. One senior official said the Israeli assessment is that Turkey is not looking for a conflict, but is trying to flex its muscles with Israel to gain influence in the Arab world.
He spoke on condition of anonymity because he was not permitted to discuss the matter publicly.
Aron Heller reported from Jerusalem. Associated Press writers Suzan Fraser in Ankara and Amy Teibel in Jerusalem contributed to this report.