Mr Trump took many – including the Israeli government – by surprise on Thursday when he tweeted his backing for Israel’s claim over the territory, marking a dramatic shift in policy over the status of an area captured in the 1967 Middle East war.
A German government spokesperson said Berlin “rejected unilateral steps” to redraw national boundaries, adding: “If national borders should be changed it must be done through peaceful means between all those involved.”
Echoing those concerns, the French foreign ministry said it did not recognise the Israeli annexation of the Golan Heights and Mr Trump’s statement was “contrary to international law”.
As worldwide condemnation continued to build, an EU spokesperson repeated the bloc’s longstanding policy not to recognise Israel’s sovereignty over the region.
It came as a Syrian foreign ministry source described Mr Trump’s statement as “irresponsible” and said it showed “contempt” for international law.
“The Golan was and will remain Syrian, Arab,” the source said, according to Syrian state media, describing it as a “precious piece of Syrian national land”.
The Palestinian leadership were quick to blast Mr Trump’s decision, saying it undermined the chance for peace in the region.
Palestinian spokesperson Nabil Abu Rudeineh said any action take on the decision would mark a “a violation of the UN resolutions, have no value whatsoever and would remain mere ink on paper”.
Hanan Ashrawi, a member of the Palestinian Liberation Executive Committee, meanwhile called it an “assault on international law”.
“Now that [Mr Trump] recognised Israel’s theft of Jerusalem and destroyed the chances of peace with Palestine, he’s enabling Israel to steal the Golan Heights and destroy the chances of peace with Syria,” she wrote on Twitter. ”How exactly does that serve Israel’s security and regional stability?”
Meanwhile Fatah, the Palestinian group which dominates the Palestinian Authority, accused Mr Trump of supporting colonialism and slavery and said his statement would not change the fact “[the Golan] is an occupied territory”.
According to newspaper Haaretz, leaders of the Arab Druze minority, who are largely based in the Golan Heights, condemned the announcement, saying it was “a delusional declaration of a delusional man”.
“The decision changes nothing in terms of the status of the Golan according to international law or for the Druze residents and was clearly meant to help prime minister Benjamin Netanyahu politically,” the statement, as quoted by the paper, read.
There was similar dismay in Gaza. Hamas the militant group which runs the Strip said Mr Trump’s announcement reflected American’s willingness to generally support Israeli occupation and it “would not serve security and stability in the region”.
Turkey said the statement brought the region to the edge of a new crisis, and Russia said a change in the status of the Golan Heights would be a direct violation of UN resolutions.
In a speech at a meeting of the Organisation of Islamic Cooperation, Turkish president Recep Tayyip Erdogan said: “We cannot allow the legitimisation of the occupation of the Golan Heights.”
The Kremlin said Russia hoped Mr Trump’s call to recognise Israeli sovereignty over the Golan Heights would remain just that, and not be enacted.
“It is just a call for now. Let’s hope it will remain a call,” said Kremlin spokesperson Dmitry Peskov. He also said such calls risk seriously destabilising the Middle East and harm efforts to find a peace settlement in the region.
An Iranian foreign ministry spokesperson called the move “illegal and unacceptable” while Egypt said the territorial claim went against international law.
In a tweet on Thursday, Mr Trump said that, after 52 years, it was important for the US to fully recognise Israel’s control over what he claimed was an area of “critical strategic and security importance to ... Israel and regional stability”.
Benjamin Netanyahu, the Israeli prime minister, who faces an election on 9 April, had been pressing for the US to recognise its claim to sovereignty over the Golan Heights.
Arab-Israeli lawmakers, who were less vocal in their criticism of the statement, accused Mr Trump of timing the announcement to bolster Mr Netanyahu’s chances in the elections, which he will likely win making him the longest serving prime minister in Israel’s history.
The recognition comes days before Mr Netanyahu arrives in Washington to meet with Mr Trump and address the influential American Israel Public Affairs Committee.
US and Israeli officials said they had not expected a decision until next week, during his visit to the US.
Mr Netanyahu, who has accused Iran of attempting to set up a terrorist network to target Israel from the Golan Heights, thanked Mr Trump for his support.
“At a time when Iran seeks to use Syria as a platform to destroy Israel, president Trump boldly recognises Israeli sovereignty over the Golan Heights. Thank you President Trump,” Mr Netanyahu tweeted.
The international community considers the Golan Heights to be occupied territory, and Syria has demanded its return as a condition for any future peace agreement.
After an eight-year civil war, peace talks with Israel are unlikely anytime soon. Throughout the war, Israel has carried out scores of airstrikes in Syria to prevent Iran from establishing a permanent military presence there.