US conducts new strikes on Iranian targets, officials say

Tonight's airstrikes on Iran targeted port facilities, missile and drone sites, coastal surveillance sites and air defense sites, according to two U.S. officials.

The strikes are expected to be much larger in scope and scale than the U.S. attacks on Iran in late June, according to a U.S. official.

Last month's strikes were also launched in response to Iranian aggression in the Strait of Hormuz, but officials said that more limited military action then was designed to avoid upending the memorandum of understanding with Iran.

-ABC News' Shannon Kingston and Luis Martinez

Iran's deputy foreign minister, in a statement published by the FARS news agency, is calling the U.S. strikes on Iran a serious violation of the memorandum of understanding signed last month between the U.S. and Iran.

"Iran will take decisive measures to protect its national interests and security, while issuing a serious warning about the consequences of America's breach of the treaty," the deputy foreign minister said in the statement.

Iranian officials also slammed the U.S. government's decision to revoke a license that authorized the sale of Iranian oil -- a key aspect of the MOU -- following Iran's reported missile strikes on tankers in the Strait of Hormuz.

U.S. forces are carrying out "powerful" airstrikes against Iran in response to earlier Iranian attacks on vessels in the Strait of Hormuz, U.S. Central Command said.

"U.S. Central Command forces have begun launching a series of powerful strikes against Iran to impose heavy costs for targeting and attacking commercial shipping crewed by innocent civilians in an international waterway," CENTCOM said in a social media post. "The U.S. strikes are in response to Iranian attacks on three commercial vessels that were transiting the Strait of Hormuz. Iran’s demonstrated aggression was unwarranted, dangerous, and a clear violation of the ceasefire."

There are were reports of several explosions in the southern Iranian port city of Sirik, Iranian state TV reported.