The U.S. moving its embassy would cause “significant harm to the U.S. credibility as a mediator” for peace talks between Israelis and Palestinians, said Dylan Williams, vice president of government affairs for J Street, a left-leaning pro-Israel advocacy organization.

Williams added that the move could “undermine confidence” from Palestinians and Arab countries that the U.S. would remain an impartial negotiator in efforts to create peace in the Middle East. 

“It shouldn’t be moved prior to agreement by the parties to the conflict as part of a comprehensive agreement ending their conflict,” Williams, J Street’s chief lobbyist, told Fox News. 

Williams added that such a move could also turn deadly.

“Even seemingly minor changes of Jerusalem’s status quo — either in fact or in law — have historically had the impact of sparking violence,” Williams said.

Support for Jerusalem

Millions of evangelical eyes were on Trump, waiting to see if he would keep his campaign promise to move the embassy, longtime Pastor John Hagee told Fox News ahead of the president’s official announcement. 

“I can assure you that 60 million evangelicals are watching this promise closely because if President Trump moves the embassy into Jerusalem, he will historically step into immortality,” Hagee said. “He will be remembered for thousands of years for his act of courage to treat Israel like we already treat other nations.” 

“If he does not, he will be remembered as just another president who made a promise he failed to keep which would generate massive disappointment in that strong evangelical base that went to vote for him against Hillary Clinton,” he added. 

“Trump will be remembered for thousands of years for his act of courage to treat Israel like we already treat other nations.”

– Pastor John Hagee

Hagee is the founder and senior pastor of Cornerstone Church, a megachurch in San Antonio, Texas. He founded the nonprofit Christians United for Israel in 2006, as well.

Pence became the first ever sitting American vice president to address the Israeli Knesset on Jan. 22 – and he reiterated the administration’s recognition of Jerusalem as Israel’s capital.

“I am here to convey one simple message. America stands with Israel. We stand with Israel because your cause is our cause, your values are our values, and your fight is our fight,” Pence said. “We stand with Israel because we believe in right over wrong, good over evil, and liberty over tyranny.”

A March 2016 Gallup poll found that the majority of Americans didn’t express an opinion when asked if the U.S. embassy should move from Tel Aviv to Jerusalem. But of those who did have an opinion, Americans were split with 24 percent supporting a move and 20 percent disagreeing with relocation.

Congressional authority

Trump isn’t the only president to declare his intentions to move the U.S. embassy; both former Presidents Bill Clinton and George W. Bush also pledged to move the embassy — only to abandon the idea once in the White House.

Congress approved in 1995 the funding and relocation of the embassy to Jerusalem by 1999. But the law included a stipulation, allowing for presidents to sign continuous waivers to stall the relocation. Every president since has used the waiver in an effort to avoid conflict with the peace negotiations.

Fox News’ John Roberts, Leland Vittert and The Associated Press contributed to this report.