The United States military has said it is conducting another wave of strikes on Iran, a day after launching another round of attacks.

The escalation is the most severe since both sides signed an Memorandum of Understanding (MoU) ending the fighting in mid June and has threatened a return to full fledged war.

The US military’s Central Command (CENTCOM) said on X on Wednesday that at President Trump’s direction, its forces “have started conducting additional strikes against Iran to further degrade their ability to threaten freedom of navigation in the Strait of Hormuz”.

“The United States is holding Iran accountable for recent unjustified aggression against commercial shipping and civilian crews freely navigating a vital international waterway,” CENTCOM said.

The post came shortly after Iran’s Mehr News Agency reported air defences were engaging what it described as “hostile targets” near the port city of Bandar Abbas, as well as explosions near Konarak, Chabahar and Bushehr.

Both the US and Iran have accused the other of violating the MoU, which ended fighting, lifted the US naval blockade on Iran, and opened the Strait of Hormuz, while leaving more intractable issues, like the future of Iran’s nuclear programme and administration of strait to be determined over a 60-day negotiating period.

The key point of contention appears to be over the fifth clause of the MoU, which says that Iran “will make arrangements using its best efforts for the safe passage of commercial vessels, with no charge for 60 days only, from the Persian Gulf to the Sea of Oman, and vice versa”.

Iran has interpreted the provision to mean it had sole “responsibility in determining arrangements for the safe passage of ships through the Strait of Hormuz”, Foreign Ministry spokesman Esmaeil Baghaei said Wednesday. That position has been used to justify attacks on unapproved vessels transiting the strait.

The administraiton of US President Donald has maintained the MoU requires unfettered passage to all vessels, Al Jazeera’s Kimberly Halkett reported from Washington, DC.

“Since the signing of the memorandum of understanding opening that 60-day window to allow for broader negotiations, the US has insisted that any uptick in conflict and military clashes is the result of Iran exercising sovereignty over the Strait of Hormuz,” Halkett said, “which the White House insists is an international waterway and necessary for the global economy.”

Speaking earlier on Wednesday, Trump said the exchange of attacks, which saw Iran’s Islamic Revolutionary Guard Corps (IRGC) strike US military sites in Bahrain and Kuwait, meant the ceasefire was “over”.

Still, he said he did not want a return to full-fledged war and suggested that negotiations could still continue.

Speaking from a NATO summit in Ankara, Trump also lodged a laundry list of threats against Iran.

Beyond another round of strikes, Trump said the US could reinstate its naval blockade on Iran and target its electricity and water plants – attacks that international law experts say constitute war crimes.

He also said that US forces “may take over” Iran’s Kharg Island, a prospect that would all but assuredly require boots on the ground.