U.S. President Donald Trump's decision to recognize Israel's sovereignty over the Golan Heights united Washington's Arab allies and their regional foe Iran in condemnation on Tuesday.

Saudi Arabia, the United Arab Emirates, Bahrain, Qatar and Kuwait criticized Monday's move to recognize Israel's 1981 annexation and said the territory was occupied Arab land. Riyadh and Abu Dhabi said it was an impediment to peace.

Iran echoed the comments, describing Trump's decision as unprecedented in this century.

"No one could imagine that a person in America comes and gives land of a nation to another occupying country, against international laws and conventions," President Hassan Rouhani was quoted as saying by state news agency IRNA.

Trump, with Israeli Prime Minister Benjamin Netanyahu during a visit to Washington, on Monday signed a proclamation officially granting U.S. recognition of the Golan Heights as Israeli territory.

The European members of the United Nations Security Council – France, Britain, Germany, Belgium and Poland – said they did not recognize Israel's sovereignty over the territories it has occupied since June 1967, including the Golan Heights.

"We raise our strong concerns about broader consequences of recognizing illegal annexation and also about the broader regional consequences," they said on Tuesday.

Israel captured the Golan Heights from Syria in the 1967 Middle East war and annexed it in 1981 in a move the U.N. Security Council declared unlawful.

"It will have significant negative effects on the peace process in the Middle East and the security and stability of the region," said a statement of Saudi state news agency SPA.

It described the declaration as a clear violation of the U.N. Charter and of international law.

Tens of Syrians gathered on Tuesday in the city of al-Baath in southern Quneitra province to protest the U.S. decision. 

Waving the Syrian flags, the people chanted slogans stressing that the Golan Heights are part of Syrian territory and carried banners reading "All of us for Golan" and "Golan is a Syrian area."

Trump senior adviser and son-in-law Jared Kushner visited the Gulf Arab region last month to seek support for the economic portion of a long-awaited peace proposal for the Middle East. Gulf Arab states host U.S. troops and are important for Washington's regional defense policy.

Qatar, which has been at loggerheads with other Gulf states over its policies, joined them in rejecting Trump's move and called on Israel to end its occupation of the Golan Heights and comply with international resolutions.

Lebanon said the decision contravened international law.

"The world is witnessing a black day," Lebanese President Michel Aoun wrote on Twitter during a visit to Russia.

Sayyed Hassan Nasrallah, the leader of Lebanon's Iran-backed Hezbollah movement, a key Damascus ally, said the move was evidence of U.S. "disdain and disregard" for the Arab and Muslim world and of international law.

"This absolute supporter of Israel cannot be a sponsor of the peace process and here he is today dealing a deadly blow to the so-called peace process," Nasrallah said in a televised speech.

Nasrallah said Trump had been emboldened by Arab "silence" after U.S. recognition last year of Jerusalem as the capital of Israel and warned that the West Bank, also captured by Israel in the 1967 Middle East war, could be next.

(Cover: Fences are seen on the ceasefire line between Israel and Syria in the Israeli-occupied Golan Heights, March 25, 2019. /VCG Photo)