(JTA) — J Street, the liberal Middle East policy group, condemned remarks by Palestinian Authority President Mahmoud Abbas that the Palestinians may pull out of efforts to reach a settlement. Abbas made the threat in a speech Tuesday at the Organization of Islamic Cooperation, where he also said the United States can no longer mediate peace talks because of President Donald Trump’s recent declaration that the United States recognized Jerusalem as Israel’s capital. “The United States can and must play a vital and productive role in facilitating negotiations toward a comprehensive two-state solution,” read the statement by J Street, in which the organization said it “rejects” Abbas’ threat, calling it “divisive and inflammatory rhetoric.”

While routine for centrist and right-wing organizations supportive of Israel, the strong-worded rebuke is unusual for J Street. The “harmful” actions by Trump, the statement continued, “can be overturned by future administrations and leaders who understand the value of serious diplomacy and the urgent necessity of resolving this conflict.”

In Istanbul, Abbas made no acknowledgment of Jerusalem’s significance for Jews and Israel. “Jerusalem is and will forever be the capital of the Palestinian state,” Abbas told delegates. “We do not accept any role of the United States in the political process from now on because it is completely biased towards Israel.” He added: “We will tell the Israelis that we are no longer committed to any agreement from Oslo until today.”

Abbas also said Ramallah intended to return to the United Nations to circumvent negotiations and gain full membership.