The U.S. strikes came after a cargo ship was attacked in the Strait of Hormuz.
President Donald Trump announced "major combat operations" against Iran on Feb. 28, with massive joint U.S.-Israeli strikes targeting military, government and infrastructure sites.
Delegations from the U.S. and Iran entered negotiations last month aimed at a war-ending deal based on a memorandum of understanding signed by both countries.
The U.S. and Iran have nonetheless continued to exchange relatively limited strikes despite the signing of the memorandum and amid the continuation of peace talks.
The U.S. conducted a new round of strikes on Iranian targets on Sunday, a U.S. official told ABC News.
The targets included Iranian air defense systems and IRGC small boats around the Strait of Hormuz, the official said.
The strikes were intended to degrade Iran’s ability to target commercial shipping, according to the official, who said no U.S. troops were wounded in the attacks.
-ABC News' Steve Beynon
United Nations Secretary-General Antonio Guterres said he's “deeply concerned" by the increasing attacks in Iran and warned of "catastrophic consequences" globally should parties return to "full-scale hostilities."
"I am deeply concerned by the serious escalation & renewed military confrontations in the Gulf, including the Iranian attacks on ships in the Strait of Hormuz, the attacks by the US on Iran, and the attacks by Iran on targets in the neighboring countries," Guterres wrote in a post on X Sunday. "These attacks must all stop."
"A return to full-scale hostilities would have catastrophic consequences – for the peoples of the region, for international peace & security & for the global economy. I urge Iran & the US to urgently resume negotiations & to address outstanding issues through diplomacy," Guterres further wrote.
-ABC News Claire Bower
Several Gulf states and Pakistan responded to Iranian strikes on Saturday night and Sunday with strongly worded statements.
Qatar’s Foreign Ministry called the attacks “a blatant violation of the sovereignty and territorial integrity of the targeted countries, and a flagrant breach of international law, the Charter of the United Nations, and the principles of good neighborliness.”
In a statement posted on X, the ministry said it is holding Iran legally responsible for the strikes and their fallout.
Oman’s Foreign Ministry said in a statement on X that it summoned the Iranian ambassador to protest the strikes, expressing “dismay at these irresponsible acts.”
Pakistan's foreign ministry also voiced “deep concern” over the escalation in regional tensions and urged “all sides to exercise restraint, take immediate steps towards de-escalation and uphold respective commitments under the Islamabad Memorandum of Understanding (MoU).”
Saudi Arabia’s Ministry of Foreign Affairs condemned what it called Iran’s “continued destabilizing behavior that undermines the security and stability of the region, and its violation of the principles of international law.”
-ABC News' Claire Bower
Despite IRGC claims to the contrary, the “Strait of Hormuz is open to all vessels seeking to lawfully transit the international waterway,” U.S. Central Command (CENTCOM) said in a post on X Sunday morning.
"U.S. forces are positioned and prepared to ensure that freedom of navigation remains available despite unwarranted Iranian aggression, harassment, threats, and arbitrary declarations. Iran does not control the strait,” the post reads. "Traffic is flowing.”
The Joint Maritime Information Center also says the Strait of Hormuz is open but maintains the regional threat level as “severe” as traffic has continued to flow at a trickle in recent days.
The Islamic Revolutionary Guard Corps' navy announced Saturday that the Strait of Hormuz will be closed until further notice and claimed a commercial vessel transiting the waterway was hit and "halted" by a "warning shot" it fired, according to Iranian media.
The statement also said that any U.S. or allied response would be met by "severe" retaliation.
-ABC News' Shannon Kingston
