ISTANBUL — Breaking with years of courting the United States, Palestinian President Mahmoud Abbas called Wednesday for the UN to replace Washington as a Mideast mediator and suggested he might not cooperate with the Trump administration’s much-anticipated effort to reach an Israeli-Palestinian peace deal.
At a summit in Turkey, Arab and Muslim leaders ‘‘rejected and condemned’’ President Trump’s recognition of Jerusalem as Israel’s capital — the trigger for Abbas’s sharp policy pivot — but stopped short of backing his more combative approach toward Washington.
A possible Palestinian refusal to engage with the United States and a growing backlash against Trump’s shift on Jerusalem, including from Arab allies, cast new doubt over the administration’s already seemingly remote chances of brokering a deal and succeeding where its predecessors have failed.
US State Department spokeswoman Heather Nauert said Wednesday the administration would continue to work on a Mideast plan that it believes will benefit Israelis and Palestinians. Referring to Abbas, she said that the ‘‘type of rhetoric that we heard has prevented peace in the past, and it’s not necessarily surprising that those types of things would be said.’’
In shunning the United States, Abbas would find himself in uncharted territory.
He does not have an immediate practical alternative to more than two decades of US-led negotiations on the terms of Palestinian statehood. The Palestinians seek such a state on lands captured by Israel in the 1967 Mideast war — the West Bank, Gaza Strip, and east Jerusalem.
On the other hand, Trump’s recognition of Jerusalem as Israel’s capital was decried by Palestinians and others in the region as a provocative show of pro-Israel bias, making it difficult for Abbas to justify dealing with Washington as a mediator.
Trump’s argument that his announcement does not mean an endorsement of specific boundaries of Israeli sovereignty in Jerusalem has not gained traction in the ensuing uproar.
The fate of Jerusalem is a hot-button issue in the region, and even the leaders of Saudi Arabia and Egypt — reportedly eager to help advance Trump’s Mideast efforts — cannot afford to be seen as soft on the religious claims of Muslims and political claims of Palestinians to the contested city. Israeli-annexed east Jerusalem is home to Islam’s third-holiest shrine, along with the most revered site in Judaism and a major Christian church.
Wednesday’s extraordinary summit of the 57-member Organization of Islamic Cooperation ended with a call on Trump to rescind an ‘‘unlawful decision that might trigger chaos in the region’’ and on the world to recognize east Jerusalem as the capital of a state of Palestine.
A concluding statement lacked tougher criticism of US policy contained in an earlier draft, which questioned Washington’s continued role as a Mideast mediator and warned that Trump’s shift on Jerusalem threatened global security.
Turkish President Recep Tayyip Erdogan, who hosted the summit, stuck to the harder line, saying at a news conference that it is ‘‘out of the question’’ for Washington to continue mediating between Israel and the Palestinians. ‘‘That process is now over,’’ he said.
Abbas’s speech marked a high-profile break with what had been his unwavering policy in more than a decade as Palestinian leader.
Despite setbacks, he had considered a close relationship with the United States the centerpiece of his efforts to win Palestinian statehood.
When Trump was elected a year ago, Abbas went out of his way not to criticize the new president, for fear of harming the relationship.
On Wednesday, he expressed a sense of betrayal.
‘‘We were shocked by the US administration,’’ Abbas said. ‘‘While we engaged with them in the peace process for the sake of a deal for the ages, [Trump] delivered a slap for the ages.’’
Abbas said the United States has disqualified itself as a mediator. ‘‘We will no longer accept that it has a role in the political process,’’ Abbas said.
The Palestinian leader said he remains committed to a two-state solution but that he would push for the UN to assume responsibility and ‘‘find a new mechanism’’ for resolving the conflict.
In another sign of a harder Palestinian stance, Abbas aides said earlier this week that he would not meet with Mike Pence when the US vice president visits the region, starting this weekend.
Abbas was initially to have hosted Pence in the biblical West Bank town of Bethlehem, after the vice president’s visit to Israel.
Trump’s nod to Israel on Jerusalem came at a time of mounting speculation about the terms of an Israeli-Palestinian deal the United States might propose.