Boris Johnson has said he is concerned by Donald Trump's plans to formally recognise Jerusalem as the capital of Israel during a speech later today.
The US President is also expected to approve moving the US embassy from Tel Aviv to Jerusalem, although not for several years.
The move - which he promised during his election campaign - will make the US the first country to recognise Jerusalem as Israel's capital since the creation of the state in 1948. Israeli sovereignty over the city, which is home to three of the most holy sites of Christianity, Judaism and Islam, has never been recognised internationally and all foreign embassies are based in Tel Aviv.
Israel has always regarded Jerusalem as its capital city, but the Palestinians claim East Jerusalem - which was annexed during the 1967 war - as the capital of a future Palestinian state.
His plans have concerned the foreign secretary, who told reporters: "We view the reports that we have heard with concern because we think Jerusalem obviously should be part of the final settlement between the Israelis and the Palestinians."
Leaders of the Arab world have warned it could jeopardise the fragile Middle East peace process, with US ally Saudi Arabia describing the move as "a flagrant provocation to Muslims".
This afternoon, Prime Minister Theresa May told the Commons there is no change to the UK's policy in favouring a two-state solution, and added that she intends to speak to Trump in order to make the government's position clear to him.
"Jerusalem should ultimately form a shared capital between the Israeli and Palestinian states," she added.
If May does take Trump to task over his actions, it will be the second time in a fortnight the pair have clashed, after she said the President was "wrong" to have retweeted videos posted by Britain First.