Donald Trump has announced that the United States recognises Jerusalem as the capital of Israel, and that he is moving the US Embassy there from Tel Aviv, risking a furious backlash in the Middle East.
In a highly anticipated speech at the White House, Mr Trump said recognising Jerusalem as the Israeli capital was the "right thing to do", adding that he was delivering on a promise that several former presidents had not fulfilled.
Mr Trump said he recognised that it was a sensitive issue but added it was not intended to reflect a departure from a strong US commitment to lasting peace.
It is the first time since the Israeli state's creation that the US will recognise Jerusalem as its capital.
Israel's Prime Minister, Benjamin Netanyahu, has hailed the announcement as a "historic landmark", but Hamas has said Mr Trump's decision opens the "gates of hell".
Mr Trump has said that the US was not taking any position on any "final status issues", including the specific boundaries of Israeli sovereignty in Jerusalem which he said are "subject to final status negotiations between the parties".
The move sparked warnings from Middle East and European leaders that it could derail a fledgling US-led peace effort and unleash violent protests and turmoil in the region.
Meanwhile the US State Department has warned its diplomats to avoid travel to the region amid fears of violent backlash to the decision.
Senior Trump administration officials said the US president was simply "recognising a historic and present reality". They said moving the embassy would take years, but Mr Trump had directed the US State Department to "start the process".
The status of Jerusalem is one of the most sensitive issues in the Israeli-Palestinian conflict, and Palestinian leaders insist there is no hope for a peace agreement unless they are able to set up their own capital in East Jerusalem. Israel claims the entire city as its "eternal and undivided capital".
Mr Trump said his announcement marked a "new approach" to the Israeli-Palestinian conflict.
"Every previous American president has exercised the law's waiver refusing to recognise Jerusalem as Israel's capital city.
"Some say they lacked courage... after two decades delaying recognition has done nothing to achieve peace.
"It would be folly to assume repeating this would make a better result.
"I have determined that it is time to officially recognize Jerusalem as the capital of Israel.
"While previous presidents have made this a major promise they have failed to deliver."
Mr Trump added that Jerusalem must remain a holy site for the three major religions that worship in the ancient city. The President said the US embassy would be moved to Jerusalem, saying that architects had already been tasked with designing a new building.
He pointed out that Israeli ministries, the Supreme Court, and the prime minister were in Jerusalem.
US being 'honest about a reality'
Mr Trump's move upends 70 years of US policy. Both Democratic and Republican presidents have always said that the status of the city be determined through peace negotiations.
One senior US official said: "US policy is going to be honest about a reality that Jerusalem is the capital of Israel. It has been the capital of the Israeli people since ancient times. It's undeniable, it's just a fact."
Mr Trump has not set out a timetable for moving the embassy, with one official pointing out that it took "eight years" to move the US Embassy in London.
Mr Trump's plans have reportedly sparked security warnings among US staff in the region, with personnel and their families ordered to avoid visiting Jerusalem's Old City or the West Bank for fear of getting caught up in protests.
Rex Tillerson, US Secretary of State, has said the Trump administration is very committed to the Middle East peace process and that his team are working on new approaches to brokering peace in the region.
Mr Trump also used his speech to reaffirm the US committment to a peace deal between Israel and the Palestinians.
He had a longstanding commitment to move the embassy, having repeatedly pledged to do so during last year's election campaign.
That pledge resonated with both evangelicals and leading pro-Israel Republican donors, some of whom had expressed disappointment that he did not do so immediately on taking office in January.
Jerusalem includes the holiest ground in Judaism but it is also home to Islam's third-holiest shrine and major Christian sites.
Any perceived harm to Muslim claims to the city has triggered volatile protests in the past.
Amid fears of a backlash America's current consulate in Jerusalem has already ordered US personnel and their families to avoid visiting Jerusalem's Old City or the West Bank.
In 1995 President Bill Clinton signed a law that said the US must relocate its diplomatic presence to Jerusalem unless the commander-in-chief issued a waiver on national security grounds.
Successive presidents have repeatedly signed the waiver every six months.
A senior White House official said: "This is bringing US policy fundamentally in line with the will of the American people.
"Delaying the recognition of Jerusalem has done nothing to support the peace process in two decades. The physical presence of the US embassy does not affect a peace deal. The president came to the judgment that this was the right time and the right decision to make."
Husam Zomlot, the Palestinians' chief delegate to Washington, said recognising Jerusalem as the capital of Israel was a "stab in the back".
Mr Trump spoke with Israeli Prime Minister Benjamin Netanyahu, who has long backed moving the US embassy to Jerusalem.
He also spoke ahead of the announcement to Mahmoud Abbas, the Palestinian president, and King Abdullah of Jordan.
King Abdullah, a close US ally, told Mr Trump that his decision would have a "dangerous impact on the security and stability of the Middle East" and would "undermine the efforts of the US to resume the peace process".
A spokesman for Mr Abbas condemned it as an "unacceptable action".
Mr Abbas immediately began a round of calls to Vladimir Putin, Emmanuel Macron and the Pope urging them "to intervene to prevent it from happening".DonaldTrump:RecognisingJerusalemIsrael'scapital'rightthing