PRESIDENT Donald Trump has signed a decree recognising Israel's sovereignty over the Golan Heights.

The document reverses more than a half-century of US policy as Israeli Prime Minister Benjamin Netanyahu visited the White House.

Trump, who signed the proclamation at a ceremony today, had announced the move in a tweet last week.

He had said that it was time for the US to take the step after 52 years of Israeli control of the strategic highlands on the border with Syria.

Netanyahu has pressed for such recognition for months.

However, the declaration prompted the United Nations to repeat its stance, that the "status of Golan has not changed", while Syria slammed it as a "slap" to the international community.

Recognising Israeli sovereignty over the Golan Heights makes Washington "the main enemy" of Arabs, Syria warned.

Israel captured the Golan from Syria in the 1967 Middle East war.

But its sovereignty over the territory is not recognised by the international community.

Reuters says that the official recognition appeared to be the most overt gesture by the Republican president to help Netanyahu.

Signing the document as his visitor looked over his shoulder, Trump said: "This was a long time in the making."

He handed the pen that he used for his signature to Netanyahu, and said: "Give this to the people of Israel."

Netanyahu welcomed Trump's move and said Israel has never had a better friend.

He then harked back to two previous Middle Eastern wars as the reason that Israel needs to hang on to the Golan.

"Just as Israel stood tall in 1967, just as it stood tall in 1973, Israel stands tall today. We hold the high ground and we should never give it up," Netanyahu said.

Republican Sen. Ted Cruz hailed Trump's decision as "tremendous", and he told CNN: "I think it is good policy for Israel, and it's good foreign policy for the US.

"A number of Democrats in the House have spoken in favour of that legislation. There's bipartisan agreement to do this."

However, today, United Nations Secretary-General Antonio Guterres said he is "clear that the status of Golan has not changed".

Spokesman Stephane Dujarric said: "The U.N.'s policy on Golan is reflected in the relevant resolutions of the Security Council and that policy has not changed."

The council refers to Israel as "the occupying power".

A U.N. 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.

Syria says Washington is "main enemy"
Syria said Trump's recognition of Israeli sovereignty over the Golan Heights makes Washington "the main enemy" of Arabs, and the Damascus government criticised the US decision as a "slap" to the international community.

Syria's Foreign Ministry called the decision a "blatant aggression" on its own sovereignty and territorial integrity.

The ministry says the American move represented the "highest level of contempt for international legitimacy," reports the Associated Press.

The Israeli PM arrived in Washington on Sunday for what was to have been a three-day visit.

But Netanyahu said he was cutting short his visit to Washington after a Gaza rocket attack on Israel.

Netanyahu describes Monday morning's rocket launch that struck a home in central Israel as a "criminal attack" and he's pledging to strike back hard.

He said he would return to Israel to handle the crisis shortly after his meeting with Trump.

An Israeli rescue service says the rocket from the Gaza Strip wounded seven people.

He was going to speak at the American Israel Public Affairs Committee's policy conference and was to be hosted at a White House dinner.