US President Donald Trump has recognised the disputed Golan Heights as Israeli territory in an election boost for visiting Israeli Prime Minister Benjamin Netanyahu, drawing a sharp response from Syria, which once held the strategic land.

With Netanyahu looking over his shoulder at the White House, Trump signed a proclamation officially granting United States recognition of the occupied Golan as Israeli territory – a dramatic shift from decades of US policy.

The move, which Trump announced in a tweet last Thursday, appeared to be the most overt gesture by the Republican president to help Netanyahu, who had been pressing Trump for the move since February 2017.

After 52 years it is time for the United States to fully recognize Israel’s Sovereignty over the Golan Heights, which is of critical strategic and security importance to the State of Israel and Regional Stability! — Donald J. Trump (@realDonaldTrump) March 21, 2019

Netanyahu welcomed Trump’s action and said Israel had never had a better friend. He harked back to two previous Middle Eastern wars in justifying Israel‘s need to hang on to the Golan.

Syria reacted swiftly to Trump’s proclamation, calling it a “blatant attack” on its sovereignty and territorial integrity and saying it had a right to reclaim the Golan.

The Syrian foreign minister said US recognition of Israeli sovereignty over the Golan Heights will lead to its isolation.

Minister Walid al-Moualem added: “No matter how many years have passed, this will not change the fact that the Golan is an occupied Syrian territory.”

Palestinian President Mahmoud Abbas and Gaza-based resistance faction Hamas both slammed the decision.

In a statement released by his office, Abbas said: “There is no legitimacy that can override UN Security Council resolutions, the UN General Assembly or the Arab Peace Initiative.”

Meanwhile, Ismail Haniya, the leader of Hamas in Gaza, said the Golan Heights would “forever remain an integral part of Syria”.

At the UN, Secretary-General Antonio Guterres is “clear that the status of Golan has not changed,” UN spokesman Stephane Dujarric said.

“The UN’s policy on Golan is reflected in the relevant resolutions of the Security Council and that policy has not changed,” he added.

A UN Security Council resolution adopted unanimously by the 15-member body in 1981 declared that Israel’s “decision to impose its laws, jurisdiction and administration in the occupied Syrian Golan Heights is null and void and without international legal effect”. It also demanded Israel rescind its decision.

Qatar’s Ministry of Foreign Affairs issued a statement rejecting the US move and saying the Golan Heights are occupied Arab land.

NATO ally Turkey termed the US recognition unacceptable and said it would take action against it, including at the UN, Foreign Minister Mevlut Cavusoglu said.

The US has once again ignored international law. However, this decision will never legitimize Israeli occupation. On the contrary, it will further increase tensions in the region by preventing peace efforts in the Middle East. — Mevlüt Çavuşoğlu (@MevlutCavusoglu) March 25, 2019

The Arab League condemned the move saying that “Trump’s recognition does not change the area’s status.”

The announcement triggered direct or implied criticism from European, as well as Middle Eastern, countries and organisations, including the UK, Germany, France, the European Union, Egypt, Russia and Venezuela.

The Bolivarian Republic of Venezuela categorically rejects Trump’s government intention to recognise the sovereignty of Israel over the Syrian territory of the Golan Heights, in violation of Security Council resolutions and the UN Charter.

La República Bolivariana de Venezuela rechaza categóricamente la intención del gobierno de D. Trump de reconocer soberanía de Israel sobre el territorio sirio de los Altos del Golán, en violación de resoluciones del Consejo de Seguridad y en contravención de la Carta de la ONU pic.twitter.com/xZ5WkM9WNG — Jorge Arreaza M (@jaarreaza) March 25, 2019

Elsewhere in Washington, the American Israel Public Affairs Committee, a pro-Israel group, held its annual meeting with speaker after speaker expressing US support for strong ties with the country.

“We stand with Israel because her cause is our cause, her values are our values, and her fight is our fight,” Vice President Mike Pence said on Monday.

Pence also talked tough against Iran, saying that under Trump, “America will never allow Iran to obtain a nuclear weapon.”

Netanyahu challenger Benny Gantz appeared before the gathering, and vowed to protect his country against threats from Iran and Syria. He called for unity in Israel.

“We must remember if that we want hope, we must have unity,” he said.

With election day approaching, opinion polls put Netanyahu’s right-wing Likud and Gantz’s centrist Blue and White party neck and neck.