Sheldon Adelson, right, talks with Secretary of State Rex Tillerson before a speech by President Trump in Jerusalem last May. (Evan Vucci/AP)

The U.S. Embassy in Israel will move from Tel Aviv to Jerusalem in May, coinciding with the 70th anniversary of Israeli independence, the State Department said Friday.

The embassy, initially to be located on the current premises of the U.S. Consulate in Jerusalem’s Arnona neighborhood, will expand on and near that site next year but will eventually move to new premises President Trump has said will be constructed, according to a statement issued by State Department spokeswoman Heather Nauert.

The cost of that building is expected to run into the hundreds of millions of dollars. Las Vegas casino magnate Sheldon Adelson, a major Republican donor, has offered to fund an unspecified part of the construction, according to an administration official who confirmed an Associated Press report.

Adelson is a strong supporter of Trump and Israeli Prime Minister Benjamin Netanyahu and owns a pro-Netanyahu newspaper in Israel.

Private financing of an embassy could raise significant problems. Steven Goldstein, the undersecretary of state for public affairs, said that State Department attorneys were looking at the legality of such a gift but that no formal talks about it had taken place. In recent months, Trump has criticized what he has called extravagant spending on embassies, including the $1 billion mission in London that opened last month.

The Post's Ishaan Tharoor explains the significance of recognizing Jerusalem as Israel's capital and what it means for the prospect of peace in the Middle East. (Sarah Parnass/The Washington Post)

Goldstein said Secretary of State Rex Tillerson had signed the security plan late Thursday for moving the embassy to the current consulate facility, a final hurdle for implementing the decision Trump announced in December.

“Safety and security have been and always will be primary” for Tillerson, Goldstein said. Trump’s proposed 2019 budget significantly cut funding for the protection of U.S. diplomatic facilities overseas.

The Jerusalem consulate will continue to issue visas and attend to the needs of visiting U.S. citizens, while also providing diplomatic representation to the Palestinians and administering cultural and aid programs. Ambassador David Friedman will move to the “interim Embassy” in May along with “a small staff,” the statement issued by Nauert said.

“Consulate Jerusalem will continue to operate as an independent mission with an unchanged mandate,” she said.

Trump’s announcement recognizing Jerusalem as Israel’s capital and ordering that the embassy be moved broke decades of U.S. policy. Jerusalem has long been considered a subject of final-status negotiations between Israelis and Palestinians. Both claim the city as their capital.

Trump said at the time that he believed the move would push the peace process forward, since it would take Jerusalem off the table as a subject of disagreement. The announcement was widely condemned in the Arab world and beyond. The U.N. General Assembly voted 128 to 9 in favor of a nonbinding resolution rejecting recognition of Jerusalem.

White House aide Jared Kushner, Trump’s son-in-law, has been tasked with drawing up a new Israeli-Palestinian peace proposal, expected to be presented to the two sides soon. The Palestinians, following Trump’s recognition of Jerusalem as Israel’s capital and intention to move the embassy, said the United States was no longer able to serve as an honest broker in the negotiations and has since refused to meet with senior Trump officials.

In a statement Friday, senior Palestinian negotiator Saeb Erekat said the announcement “shows the determination of the U.S. administration to violate international law, destroy the two-state solution, and provoke the feelings of the Palestinian people, as well as of all Arabs, Muslims and Christians around the globe.”

“East Jerusalem is the capital of the State of Palestine,” the statement said, “an integral part of the territory occupied by Israel since 1967.”

Nikki Haley, the U.S. ambassador to the United Nations, rejected the notion that the United States gave up leverage in future negotiations with a policy change sought by Israel.

Speaking Thursday evening during a question-and-answer session at the University of Chicago’s Institute of Politics, Haley said, “I think multiple presidents struggled with it out of the whole fear doctrine that the sky was going to fall. The sky is still up there. It didn’t fall. And now what we have is a time when negotiations can start.”

Update: This story has been updated with additional information about the Jerusalem consulate’s duties.

Anne Gearan and Ruth Eglash in Jerusalem contributed to this report.