If he was hoping for thunderous applause from American Jews, President Trump may be disappointed.

His announcement on Wednesday that he will recognize Jerusalem as Israel’s capital went down well with those on the political right, who have urged the step for years. They will be telling him so at the White House Hanukkah party on Thursday, they said.

But other Jewish leaders said they were more worried than glad, fearing that the precipitous step would inflame tensions in the region, provoke more terrorism, put peace with the Palestinians even farther out of reach, and worsen the diplomatic isolation of both Israel and the United States. They say they wish he had held off, as previous presidents have done.

“Jerusalem has always been the most delicate issue in every discussion about peace,” said Rabbi Rick Jacobs, president of the Union for Reform Judaism, the largest branch of American Judaism. “So we’re very concerned that the announcement will either delay or undermine the very, very important resuming of a serious peace process.”

Debra DeLee, the president of Americans for Peace Now, an affiliate of the Israeli peace group Shalom Achshav, said, “Trump is causing severe damage to the prospects of Middle East peace, imperiling lives, and degrading U.S. leadership.”