Abbas’ aide Majdi Khaldi said on Tuesday the U.S. would lose credibility as a Mideast mediator if Trump goes ahead with the move.

East Jerusalem, captured by Israel in 1967, is home to major Muslim, Christian and Jewish holy sites. The Palestinians seek it as a future capital, while Israel claims all of Jerusalem as its capital.

Arab League representatives were to discuss the Jerusalem controversy on Tuesday. The organization said on Monday that Trump’s possible recognition would constitute “naked aggression” against Muslims and Arabs.