Qatar's foreign minister, Sheikh Mohammed bin Abdulrahman al-Thani, said Trump's undertaking was a "death sentence for all who seek peace" and called it "a dangerous escalation".
Turkey said Trump's move was "irresponsible".
"We call upon the U.S. Administration to reconsider this faulty decision which may result in highly negative outcomes and to avoid uncalculated steps that will harm the multicultural identity and historical status of Jerusalem," the Turkish foreign ministry said in a statement.
A few hundred protesters gathered outside the U.S. consulate in Istanbul, a Reuters cameraman at the scene said. The protest was largely peaceful, though some of the demonstrators threw coins and other objects at the consulate.
Iran "seriously condemns" Trump's move as it violates U.N. resolutions on the Israel-Palestinian conflict, state media reported. Supreme Leader Ayatollah Ali Khamenei said earlier in the day that the United States was trying to destabilize the region and start a war to protect Israel's security.
In Southeast Asia, the leaders of Muslim-majority Indonesia and Malaysia denounced Trump's action.
"This can rock global security and stability," Indonesian President Joko Widodo, leader of the world's largest Muslim-majority nation, told a news conference in which he called for the United States to reconsider its decision.
British Prime Minister Theresa May disagreed with Trump's embrace of Jerusalem as Israel's capital before a final-status agreement as this was unlikely to help nurture peace in the region, her spokesman said.
However, May's spokesman welcomed Trump's stated wish to end the conflict and his acknowledgement that the final status of Jerusalem, including boundaries within the city, must be subject to negotiations between Israelis and Palestinians.
French President Emmanuel Macron said he did not support Trump's "unilateral" move.
"The status of Jerusalem is a question of international security that concerns the entire international community. The status of Jerusalem must be determined by Israelis and Palestinians in the framework of negotiations under the auspices of the United Nations," Macron told reporters in Algiers.
"France and Europe are attached to a two-state solution - Israel and Palestine - living side by side in peace and security within recognised international borders with Jerusalem the capital of both states," he said.
"For now, I urge for calm and for everyone to be responsible. We must avoid at all costs avoid violence and foster dialogue," he said.
U.N. Secretary-General Antonio Guterres said there was no alternative to a two-state solution and Jerusalem was a final-status matter only to be settled through direct talks.
"I have consistently spoken out against any unilateral measures that would jeopardize the prospect of peace for Israelis and Palestinians," Guterres said. "I will do everything in my power to support the Israeli and Palestinian leaders to return to meaningful negotiations."