China joined other nations in warning US President Donald Trump against his plan to recognise Jerusalem as Israel's capital, saying it could fuel tensions in the region.
"We are concerned about the possible escalation of tensions," foreign ministry spokesman Geng Shuang told a regular news briefing.
But a senior administration official said in Washington that Trump would make the announcement – ignoring frantic warnings from US allies in the region and around the world – at 1pm (Thursday 2am HK time) from the White House.
"He views this as a recognition of reality, both historic reality," the source added, "and modern reality".
Plunging further into a decades-long dispute over a city considered holy by Jews, Muslims and Christians, Trump will also order to begin planning to move the US embassy from Tel Aviv to Jerusalem.
"It will be a matter of some years, it won't be months, it's going to take time," the official said.
In a frantic series of calls, the leaders of Saudi Arabia, Egypt, Jordan, the European Union, France, Germany and Turkey all warned Trump against the move.
Anticipating protests, US government officials and their families have been ordered to avoid Jerusalem's Old City and the West Bank.
Trump's move comes close to fulfilling a campaign promise, and will delight his political donors and the conservative and evangelical base so vital for the embattled president.
Most of the international community does not formally recognise 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.
Trump "is prepared to support a two State solution... If agreed to by the two parties."
Critics say Trump's approach is more like "splitting the baby" and could also extinguish his own much-vaunted efforts to broker Middle East peace while igniting the flames of conflict in a region already reeling from crises in Lebanon, Syria, Iraq, Yemen and Qatar.
The armed Islamist Hamas movement has threatened to launch a new "intifada" or uprising. (AFP)