Syria’s state-run media published photos of citizens marching in the streets on Tuesday to protest U.S. President Donald Trump’s proclamation recognizing Israeli sovereignty over the Golan Heights. The Syrian regime’s patrons in Iran denounced the decision, while the increasingly Islamist government of Turkey vowed to fight the U.S. and Israel at the United Nations.

According to Syrian media, large demonstrations took place in several cities on Tuesday morning. The demonstrators waved Syrian and Palestinian flags and carried banners proclaiming, “Golan is Syrian.”

An official with the Syrian Foreign Ministry described the American proclamation as “a blatant attack on the sovereignty and territorial integrity of the Syrian Arab Republic and a disregard for all international reactions denouncing this decision.”

The Syrian official denounced the United States as “the main enemy of the Arabs” and said Trump’s support for Israeli sovereignty over the Golan Heights is a “disgraceful slap to the international community.”

Iranian President Hassan Rouhani on Tuesday described Trump’s action as an imperialist outrage “unprecedented in the current century.”

“No one could imagine that a person in America comes and gives the land of a nation to another occupying country, against international laws and conventions,” Rouhani said.

Saudi Arabia and the Sunni states of the Gulf Cooperation Council (GCC) joined Iran and estranged GCC member Qatar in objecting to President Trump’s proclamation, albeit in less histrionic terms. The Saudi state news agency predicted the Golan declaration “will have significant negative effects on the peace process in the Middle East and the security and stability of the region.”

Jordan, generally a reliable U.S. ally but interested in restoring relations with the Assad regime in Syria, also refused on Monday to recognize the Golan Heights as Israeli territory.

The most heated denunciations of the Golan proclamation arguably came from Turkey, whose President Recep Tayyip Erdogan is angling for a position as champion of the Islamic world. Turkey has long disliked the Assad regime in Syria, but Turkish officials seemed angrier on Monday and Tuesday than their Syrian counterparts over the disposition of the Golan Heights.

“Attempts by the U.S. to legitimize Israel’s actions against international law will only lead to more violence and pain in the region,” Turkish Foreign Minister Mevlut Cavusoglu predicted.

Cavusoglu declared Turkish support for Syria’s “territorial integrity,” presumably with the exception of whatever Syrian soil Turkish forces must roll across on their way to attacking the Syrian Kurds.

Turkey’s authoritarian President Recep Tayyip Erdogan vowed over the weekend to challenge the U.S. and Israel at the United Nations.

“The U.N. has the final verdict on this,” Erdogan said. “It is not possible for the U.N. General Assembly to approve the issue.”

Erdogan and Cavusoglu both contemptuously dismissed Trump’s signature on the Golan proclamation as a pre-election gift to Israeli Prime Minister Benjamin Netanyahu.

“Trump wants to present the Golan Heights to Netanyahu as a present on a gold platter,” Erdogan said.