Several close U.S. allies urged a return to the negotiating table in the wake of American strikes on Iran that fueled fears of a wider conflict, while noting the threat posed by Tehran’s nuclear program. Some countries and groups in the region, including those that support Iran, condemned the move while also urging de-escalation.

U.S. President Donald Trump had said Thursday that he would decide within two weeks whether to get involved in Israel’s war with Tehran. In the end, it took just days. Washington hit three Iranian nuclear sites early Sunday.

While the amount of damage remained unclear, Iranian Foreign Minister Abbas Araghchi said the U.S. had “crossed a very big red line,” the time for diplomacy was over and Iran had the right to defend itself.

Some have questioned whether a weakened Iran would capitulate or remain defiant and begin striking with allies at U.S. targets scattered across the Gulf region.

Here is a look at reactions from governments and officials around the world.

U.N. Secretary General Antonio Guterres said he was “gravely alarmed” by the use of force by the United States.

“There is a growing risk that this conflict could rapidly get out of control — with catastrophic consequences for civilians, the region, and the world,” he said in a statement on the social media platform X. “I call on Member States to de-escalate.”

“There is no military solution. The only path forward is diplomacy.”

British Prime Minister Keir Starmer warned of escalation beyond the Middle East as he called for all sides to negotiate a diplomatic end to the crisis, saying stability was the priority in the volatile region.

The U.K., along with the European Union, France and Germany, tried unsuccessfully to broker a diplomatic solution in Geneva last week with Iran.

Starmer said Iran’s nuclear program posed a grave threat to global security.

“Iran can never be allowed to develop a nuclear weapon and the U.S. has taken action to alleviate that threat,” Starmer said.

Dmitry Medvedev, who serves as deputy head of President Vladimir Putin’s Security Council, said several countries were prepared to supply Tehran with nuclear weapons.

He didn’t specify which countries, but said the U.S. attack caused minimal damage and would not stop Tehran from pursuing nuclear weapons.

Russia’s Foreign Ministry said it “strongly condemned” the airstrikes and called them a “a gross violation of international law, the U.N. Charter, and U.N. Security Council resolutions.”

The Iraqi government condemned the U.S. strikes, saying the military escalation created a grave threat to peace and security in the Middle East. It said it poses serious risks to regional stability and called for diplomatic efforts to de-escalate the crisis.

“The continuation of such attacks risks dangerous escalation with consequences that extend beyond the borders of any single state, threatening the security of the entire region and the world,” government spokesman Bassem al-Awadi said in the statement.

Saudi Arabia, which previously condemned Israel’s strikes on Iran’s nuclear facilities and military leaders, expressed “deep concern” about the U.S. airstrikes, but stopped short of condemning them.

“The Kingdom underscores the need to exert all possible efforts to exercise restraint, de-escalate tensions, and avoid further escalation,” the Foreign Ministry said in a statement.

China condemned U.S. strikes on Iran, calling them a serious violation of international law that further inflamed tensions in the Middle East.

In a statement, the Chinese Foreign Ministry urged all parties — especially Israel — to implement a cease-fire and begin dialogue.

“China is willing to work with the international community to pool efforts together and uphold justice, and contribute to the work for restoring peace and stability in the Middle East,” the ministry said.

The European Union’s top diplomat said Iran must not be allowed to develop a nuclear weapon, but she urged those involved in the conflict to show restraint.

“I urge all sides to step back, return to the negotiating table and prevent further escalation,” EU foreign policy chief Kaja Kallas said in a post on social media.

Japanese Prime Minister Shigeru Ishiba told reporters Sunday that it was crucial to calm the situation as soon as possible, adding that the Iranian nuclear weapons development also must be prevented.

Ishiba, asked if he supports the U.S. attacks on Iran, declined to comment.

Pope Leo XIV made a strong appeal for peace during his Sunday Angelus prayer in St. Peter’s square, calling for international diplomacy to “silence the weapons.”

After an open reference to the “alarming” situation in Iran, the first American pontiff stressed that “today more than ever, humanity cries out and invokes peace and it is a cry that demands reason and must not be stifled.”

Pope Leo urged every member of the international community to take up their moral responsibility to “stop the tragedy of war before it becomes an irreparable abyss.”