President Donald Trump will recognize Jerusalem as Israel's capital Wednesday, upending decades of careful US policy and ignoring dire warnings of a historic misstep that could trigger a surge of violence in the Middle East.
A senior administration official said Trump would make the landmark announcement -- which flies in the face of warnings from America's allies across the region and the world -- at 1 pm (1800 GMT) from the White House.
"He will say that that the United States government recognizes that Jerusalem is the capital of Israel," a senior administration official said, speaking on condition of anonymity.
"He views this as a recognition of reality, both historic reality," the source added, "and modern reality."
Plunging further into a bitter centuries-old argument between Jews, Muslims and Christians, Trump will also order planning to begin on moving the US embassy from Tel Aviv to Jerusalem.
"It will take some time to find a site, to address security concerns, design a new facility, fund a new facility and build it," the official said, indicating that the move will not be immediate.
"It will be a matter of some years, it won't be months, it's going to take time."
The status of Jerusalem is a central issue in the Israeli-Palestinian conflict, with both sides claiming the city as their capital, and expectations of Trump's announcement have roiled the combustible region.
In a frantic series of calls on its eve, the leaders of Saudi Arabia, Egypt, Jordan, the EU, France, Germany and Turkey all warned Trump against the move.
Anticipating widespread demonstrations, US government officials have been ordered to avoid Jerusalem's Old City and the West Bank.
But Trump's move comes close to fulfilling a campaign promise and will delight his political donors and the conservative and evangelical base that is so vital for the embattled president.
Most of the international community does not formally recognize Jerusalem as Israel's capital, insisting the issue can only be resolved in final status negotiations.
US officials talk of "threading the needle" -- fulfilling Trump's campaign pledge, while keeping the peace process on the rails.
The White House argues that such a move would not prejudge final talks and would represent the reality that west Jerusalem is and will continue to be part of Israel under any settlement.