The US State Department said on Friday it was going to bring forward the — internationally contested — relocation of its embassy in Israel to Jerusalem, describing the move as a "historic step."

"The opening will coincide with Israel's 70th anniversary," State Department spokeswoman Heather Nauert said. The anniversary of the country's founding falls on May 14.

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The move will come much earlier than first expected. During a visit to Jerusalem last month, US Vice President Mike Pence said he did not expect the embassy relocation to be completed before the end of 2019.

Israeli Prime Minister Benjamin Netanyahu welcomed the announcement, thanking US President Donald Trump for his "leadership" and "friendship."

According to Nauert, the embassy will initially be part of the expanded US consular facilities in Jerusalem's Arnona neighborhood. However, officials are also looking for a permanent site for what she described as a "longer-term undertaking."

Meanwhile, the interim embassy would contain office space for the ambassador and a small staff.

Reuters news agency, citing a US official speaking on condition of anonymity, reported that the US would keep its separate consulate in East Jerusalem open to serve Palestinians. Sources also said US Ambassador to Israel David Friedman would continue to live at his residence in the Tel Aviv neighborhood of Herzliya for security reasons and commute to Jerusalem.

Trump broke with decades of policy when he announced in December that he would relocate the US diplomatic mission and recognize Jerusalem as the Israeli capital. Prior to the announcement, the city's status — which has been one of the thorniest issues in the decades-long peace process — was earmarked as something for negotiation in a two-state peace process.

The move dismayed Palestinians, who see the eastern part of the city as their capital, and infuriated Arab countries.

The announcement sparked days of unrest in the Palestinian territories.

PLO: Relocation timing a 'blatant provocation'

The Palestine Liberation Organization (PLO) decried Friday's announcement as a "provocation to all Arabs."

Palestinian negotiator Saeb Erekat said the timing of the US Embassy relocation "shows the determination of the US administration to violate international law, destroy the two-state solution, and provoke the feelings of the Palestinian people."

Read more: PLO recognition threat against Israel: Posturing or hard-line diplomacy?

The anniversary of Israel's founding also marks the Palestinian commemoration of Nakba, the mass migration of some 700,000 Palestinians who fled their homes following the creation of Israel and the onset of the 1948 Arab-Israeli war.

Nabil Abu Rdainah, a spokesman for Palestinian President Mahmoud Abbas, said: "This is an unacceptable step. Any unilateral move will not give legitimacy to anyone and will be an obstacle to any effort to create peace in the region."

Abbas has already said the embassy move demonstrates that the US can no longer be an honest broker in the peace negotiations.

Questions over Jerusalem embassy financing

According to the AP news agency, the Trump administration and State Department lawyers are considering an offer from Sheldon Adelson, an influential Republican Party donor and Las Vegas casino magnate, to foot at least part of the bill for the new embassy.

According to officials, Adelson, a staunch Israel supporter, has offered to pay the difference between running the new Jerusalem embassy and whatever funds the government can raise for the move.

Allowing private citizens to foot the bill for an official government building would present a radical departure from traditional practice. Moreover, given Adelson's publicized affiliation with figures on the right-wing of Israeli politics, the proposal would add another layer of controversy to the new embassy.

dm/sms (AP, AFP, Reuters, dpa)