December 5, 2017, 11:51 pm
Turkey's president has warned it could sever ties with Israel if the US recognises Jerusalem as its capital.
Recep Tayyip Erdogan said such a move would cross a "red line" for Muslims.
Donald Trump called world leaders on Tuesday amid a growing chorus of warnings against taking the step.
Reports say the president will dramatically shift the US position on the status of Jerusalem this week. Its fate is one of the thorniest issues between Israel and the Palestinians.
Israel has always regarded it as its capital city, while the Palestinians claim East Jerusalem as the capital of a future Palestinian state.
If Washington recognises Jerusalem as Israel's capital, it would be the first country to do so since the foundation of the state in 1948.
In a televised speech, Mr Erdogan addressed the US president directly, saying "Mr Trump! Jerusalem is a red line for Muslims.
"We could go as far as cutting diplomatic ties with Israel over the issue," he added.
Turkey and Israel restored diplomatic relations last year, six years after Turkey severed ties in protest at the killing of nine pro-Palestinian Turkish activists in clashes with Israeli commandos on board a ship trying to break Israel's naval blockade of Gaza.
Israeli minister Naftali Bennett rebuffed the Turkish president, saying: "Unfortunately, Erdogan does not miss an opportunity to attack Israel.
"There will always be those who criticise, but at the end of the day it is better to have a united Jerusalem than Erdogan's sympathy."
The White House said Mr Trump was holding calls with world leaders including Israeli Prime Minister Benjamin Netanyahu and Palestinian Prime Minister Mahmoud Abbas, a day before his anticipated announcement.