World leaders including Theresa May, Palestinian President Mahmoud Abbas and France's Emmanuel Macron have condemned Donald Trump's "unhelpful" decision to recognise Jerusalem as Israel's capital.
Defying warnings that the move could increase tensions in the region and potentially spark violence, the US president announced on Wednesday that his country would be the first to recognised Jerusalem in such a way.
In a speech in Washington DC, Mr Trump said: "I have determined that it is time to official recognise Jerusalem as the capital of Israel."
He also confirmed his oft-repeated campaign promise to move the US embassy from Tel Aviv to Jerusalem in his speech on Wednesday.
Palestinians took to the streets in the Gaza Strip to protest the decision, burning the American and Israeli flags in response to Mr Trump's move.
Eight nations, including the UK, France, Italy, and Uruguay, have requested an emergency meeting of the UN Security Council following the announcement.
President Abbas said Trump's announcement was a "declaration of withdrawal" from the peace process.
But Israeli Prime Minister Benjamin Netanyahu described the recognition of Jerusalem as Israel's capital as an "historic day" and an "important step towards peace".
"There is no peace that doesn't include Jerusalem as the capital of the state of Israel," he said.
The move has provoked further condemnation from other world leaders with many echoing Mr Abbas' fears the US president's decision could derail the fragile Middle East peace process.
Theresa May said she disagreed with Mr Trump's "unhelpful" decision.
In a statement, Mrs May said: "We disagree with the US decision to move its embassy to Jerusalem and recognise Jerusalem as the Israeli capital before a final status agreement.
"We believe it is unhelpful in terms of prospects for peace in the region. The British Embassy to Israel is based in Tel Aviv and we have no plans to move it.
"Our position on the status of Jerusalem is clear and long-standing: it should be determined in a negotiated settlement between the Israelis and the Palestinians, and Jerusalem should ultimately be the shared capital of the Israeli and Palestinian states."
French president Emmanuel Macron described it as "a regrettable decision that France does not approve."
Mr Trump's plan also undermines the US's role as a mediator in Israel-Palestine negotiations.
President Trump's announcement breaks from Washington's carefully maintained position of neutrality over the status of Jerusalem. US administrations have, until now, asserted that the city's ultimate fate must be determined through Israeli-Palestinian negotiation.
The US president insisted his decision was the "right thing to do" and a "long overdue step to advance the peace process," stressing the US was not taking a position on specific boundaries or the resolution of contested borders.
He said he intends "to do everything" in his power to help forge a peace deal between Israelis and Palestinians and was "prepared to back a two-state solution."
UN Secretary-General Antonio Guterres warned: In this moment of great anxiety, I want to make it clear: there is no alternative to the two-state solution. There is no Plan B."
Mr Trump said American policy of the last two decades had done nothing to advance peace in the region.
"For over 20 years every previous American president has exercised the laws waiver refusing to move the US embassy to Jerusalem or to recognise Jerusalem as Israel's capital city.
"After more than two decades of waivers we're no closer to a lasting peace agreement between the Israelis and the Palestinians, and it would be folly to assume that repeating the exact same formula would now produce a different or better result.
"While previous presidents have made this a major campaign promise, they failed to deliver. Today, I am delivering. I've judged this cause of action to be in the best interests of the united states of america and the pursuit of peace between Israeli and the Palestinians."
The ancient city of Jerusalem lies at the heart of the Israeli-Palestinian conflict.
Israel captured East Jerusalem - home to important Jewish, Christian and Islamic shrines - in the 1967 Middle East War and later annexed it - a move that is not recognised internationally.
Israel has always regarded Jerusalem as its capital, but Palestine wants the East Jerusalem - home to some 400,000 Palestinians - to be the capital of a future independent Palestine state.
Reaction from around the world
Palestinian prime minister Mahmoud Abbas, said it would "destroy the peace process and the two-state solution."
Hamas, the militant group, threatened a new "intifada" -- warning that Palestinians must either "remain or perish".
French president Emmanuel Macron said "France disagrees with the decision of the United States" and said the move "contravenes international law and UN Security Council resolutions."
Prime minister Theresa May called Donald Trump's decision "unhelpful".
Turkey described it as "irresponsible" and "bears the risk of completely destroying the ground for peace." Turkey's foreign minister says Trump's recognition of Jerusalem as the capital of Israel doesn't automatically make it so.
Egypt's Foreign Ministry said Trump's decision is a violation of international resolutions on the city's status.
EU Foreign Affairs Chief Federica Mogherini said: “The aspirations of both parties must be fulfilled and a way must be found through negotiations to resolve the status of Jerusalem as the future capital of both states."
Lebanon’s Prime Minister Saad al-Hariri said Lebanon rejected the decision and had the utmost solidarity with the Palestinian people.
Iran's Ministry of Foreign Affairs said it “seriously condemns" Trump's decision.
US ally Jordan said it stokes anger in the region and declared it “legally null”.
ITV News Correspondent Dan Rivers reports from Jerusalem on the possible repercussions for peace in the region