United States President Donald Trump has officially recognized Israeli sovereignty over the occupied Golan Heights, seized from Syria in 1967, in a move hailed as "historic" by Israel's prime minister, the BBC reports.

Benjamin Netanyahu, who faces an election next month, was by Trump's side as he signed the proclamation.

Syria said Trump's decision was "a blatant attack on its sovereignty".

Israel annexed the Golan Heights in 1981, in a move that is not recognized internationally.

A spokesman for United Nations Secretary-General Antonio Guterres said on Monday, March 25 he was "clear that the status of Golan has not changed".

For decades, Washington took the same line as the UN, but last week Trump announced his plan to overturn decades of US policy in a tweet.

In response, Syria has vowed to recover the area "through all available means".

But Netanyahu told reporters gathered in Washington on Monday that Israel "shall never give it up".

"Your proclamation comes at a time when Golan is more important than ever for our security," he said, citing threats from Iranian forces in Syria.

It is, he added, "a two-fold act of historic justice".