But even with those caveats, Mr. Trump’s decision seems likely to disrupt, if not dissolve, the peace effort. Administration officials said they expected the Palestinians to walk away from the process, at least for now. The White House is girding itself for an eruption of violence, coordinating plans with several agencies to protect American citizens abroad.

“You can finesse this all you want, but Jerusalem doesn’t allow for any finesse,” said Martin S. Indyk, a former American ambassador to Israel. “They can try to limit the damage all they want, but they won’t be able to, because Jerusalem is such a hot-button issue.”

To some extent, Mr. Trump’s willingness to take such a risk underscores how little progress his peace negotiators — led by his son-in-law, Jared Kushner — have made. Six months ago, when the president last had to decide whether to sign a waiver to keep the embassy in Tel Aviv, Mr. Kushner prevailed on Mr. Trump to do so, in the interest of the peace process.

Since then, however, the administration’s efforts have shown little evidence of narrowing the differences between Israelis and Palestinians. Mr. Kushner and Jason D. Greenblatt, the president’s special envoy, supported Mr. Trump’s decision, officials said.

Mr. Trump’s pledge was extremely popular with evangelicals and pro-Israel backers, including the casino magnate Sheldon Adelson, who donated $25 million to a political action committee supporting Mr. Trump during the presidential campaign. Mr. Adelson expressed anger when Mr. Trump signed the waiver in June to keep the embassy in Tel Aviv.

The White House, which has done little to lay the groundwork for the move, on Tuesday contacted pro-Israel leaders from the Jewish and Christian communities to invite them to a conference call set for Wednesday afternoon, according to an invitee who spoke about it on condition of anonymity because he did not want to jeopardize his relationship with Mr. Trump’s team.

Mr. Klein was among several supporters who questioned why the embassy move would take several years. Former diplomats have said that the United States could relocate the embassy simply by hanging a new sign outside the American consulate in Jerusalem.