(Xinhua)    07:45, December 14, 2017

Participants pose for a group photo during the extraordinary summit of the Organization of Islamic Cooperation (OIC) in Istanbul, Turkey, on Dec. 13, 2017. Turkish President Recep Tayyip Erdogan on Wednesday urged the Islamic world to recognize Jerusalem as the capital of Palestine, while Palestinian President Mahmoud Abbas refused any U.S. involvement in the peace process. (Xinhua/Anadolu Agency)

ISTANBUL, Dec. 13 (Xinhua) -- A summit of Islamic countries held in Istanbul on Wednesday declared East Jerusalem as the capital of the State of Palestine to counter a U.S. decision in favor of Israel.

The summit of the Organization of Islamic Cooperation (OIC) also invited all countries in the world to "recognize the State of Palestine and East Jerusalem as its occupied capital," said the draft final communique unveiled at the conclusion of the one-day meeting.

The heads of state and government present at the summit rejected as "null and void" and condemned "in the strongest terms" the unilateral decision by U.S. President Donald Trump to recognize Jerusalem as the capital of Israel, the communique said.

The leaders described the U.S. move as an attack on the rights of the Palestinian people, a "deliberate undermining" of all peace efforts, "an impetus to extremism and terrorism," and a threat to international peace and security.

They reaffirmed their commitment to a two-state solution to the decades-old conflict between the Israelis and the Palestinians, with East Jerusalem as the capital of the State of Palestine, warning Washington of "all the consequences" of not retracting its decision.

Without stepping back, the U.S. would lose its role as a sponsor of the peace process, cautioned the leaders from the OIC, the second largest inter-governmental organization after the United Nationswith a membership of 57 states spread over four continents.

Addressing a press conference following the summit, Palestinian President Mahmoud Abbas said the United Statesis no longer an honest broker of peace.

"We cannot accept any more the United States as a peace broker, because basic requirements of being a peace broker are to be honest and objective," he said.

Trump broke long-held U.S. practice by announcing his decision on Dec. 6 to recognize Jerusalem as the Israeli capital and move U.S. embassy from Tel Aviv to the holy city, sparking days of violent clashes in the Gaza Strip and West Bank as well as protests in other Arab countries.

Speaking at the press conference, Turkish President Recep Tayyip Erdogan also signaled the end of U.S. mediating role, "because a peace process can only be conducted with an objective mediator."

Saying Trump "will play and dance by himself," Erdogan urged the U.S. president to reverse his "wrong decision," stressing that "insisting on a mistake has no benefit to anyone."