Donald Trump will announce later today that the US recognises Jerusalem as the capital of Israel and will move its embassy there, breaking with decades of US and international policy and potentially stirring unrest.
Despite warnings from Western and Arab allies, Trump will in a White House speech at 1pm US time (18.00 GMT) direct the State Department to begin looking for a site for an embassy in Jerusalem as part of what is expected to be a process lasting years to relocate diplomatic operations from Tel Aviv.
Trump is to sign a national security waiver delaying a move of the embassy, since the US does not have an embassy structure in Jerusalem to move into. A senior administration official said it could take three to four years to build an embassy.
But Trump's decision, a core promise of his campaign last year, will upend decades of American policy that has seen the status of Jerusalem as part of a two-state solution for Israelis and Palestinians, who want East Jerusalem as their capital.
Washington's Middle East allies all warned against the dangerous repercussions of his decision when Trump spoke to them on Tuesday.
'The president believes this is a recognition of reality,' said one official, who briefed reporters on Tuesday about the announcement. 'We're going forward on the basis of a truth that is undeniable. It's just a fact.'
Senior Trump administration officials said Trump's decision was not intended to tip the scale in Israel's favour and that agreeing on the final status of Jerusalem would remain a central part of any peace deal between Israel and the Palestinians.
In defending the decision, the officials said Trump was basically reflecting a fundamental truth: That Jerusalem is the seat of the Israeli government and should be recognised as such.
Yet the Palestinians have said the move would mean the 'kiss of death' to the two-state solution.
The mere hint of his decision to move the embassy in the future set off alarm bells around the Middle East, raising the prospect of violence, with security tightened at American locations and people advised not to venture into Jerusalem's Old City.
'Our Palestinian people everywhere will not allow this conspiracy to pass, and their options are open in defending their land and their sacred places,' said Hamas chief Ismail Haniyeh.
Last night a spokesperson for the Palestinian President Mahmoud Abbas said that Trump had informed him that the move would go ahead.
'President Abbas warned of the dangerous consequences such a decision would have to the peace process and to the peace, security and stability of the region and of the world,' the spokesperson said.
The leaders of Turkey and US allies Saudi Arabia and France urged the US President not to make the highly controversial moves which would infuriate the Palestinians in the sensitive region, while evangelical Christians and Israelis lobbied for the change amid confusion after Trump appeared to miss the deadline for the embassy shift on Monday.
The US, the UN and almost every country in the world currently refuse to accept that Jerusalem is Israel's capital, with most major embassies functioning in the sea-side business capital, Tel Aviv. International consensus is that East Jerusalem is occupied territory, just like the West Bank.
While Israel considers Jerusalem its 'eternal, undivided capital', the Palestinians regard the east of the city – occupied by Israel in the 1967 Six Day War – to be the capital of any future Palestinian state.
The debate about the embassy's location goes back to 1995, when the US Congress approved the Jerusalem Embassy Act, which requires that the American embassy be moved from Tel Aviv to Jerusalem.
Since then, successive US presidents – both Democratic and Republican – have exercised a waiver delaying its implementation every six months on national security grounds, and official US policy does not recognise Jerusalem as Israel's capital.
There has been speculation for the past two years about whether Trump would fulfill his campaign promise to make the move, as well as recognise Jerusalem as Israel's capital. Some reports say the Trump will dramatically shift the US position on the status of Jerusalem this week.
Today, the Turkish president Recep Tayyip Erdogan said such a move would cross a 'red line' for Muslims.
'Mr Trump! Jerusalem is a red line for Muslims,' Erdogan said in a televised speech yesterday.