Iran’s top negotiator, Mohammed Bagher Ghalibaf, has declared that the country’s armed forces have “complete freedom of action” against the “enemy’s aggression”, after a day of attacks by the United States killed seven Iranian troops.

The attacks on Wednesday were the latest in days of escalating hostilities between Washington and Tehran that appear to have doomed an interim peace deal they agreed to on June 17.

The US announced several rounds of air strikes on Iran overnight on Tuesday and again on Wednesday, saying its forces hit military targets in Iranian coastal areas near the Strait of Hormuz and on the Greater Tunb island.

Iran’s army said one attack struck a barracks in Bampour in the country’s southeast, killing seven personnel from the 388th Brigade and injuring several others. It pledged to deliver “a decisive response… at the appropriate time”.

Iranian media also reported that an overnight US attack hit a wheat storage facility in the  western Khuzestan province, which the US military denied.

The US announced its latest wave of strikes on Wednesday had begun at 10:30pm Iranian time (19:00 GMT), as Iranian media reported explosions in or near Bandar Abbas, Chabahar and Ahvaz.

Earlier, the US military also said it had redirected two commercial vessels as part of a renewed blockade on Iranian ports, which it began enforcing the night before.

Return to negotiations ‘extremely difficult’

Tehran said the repeated waves of US attacks had voided the memorandum of understanding with Washington that had underpinned the fragile ceasefire. Ghalibaf said Iran was “in an essential and existential war with America” and had no reason to continue adhering to the terms of the peace agreement.

Ministry of Foreign Affairs spokesman Esmaeil Baghaei said Iran had abandoned its commitments under the memorandum because the US had reneged on its side of the deal.

“Our commitments remain in effect only as long as the other side fulfils its pledges,” Baghaei said.

He said Tehran had no plans to engage in further talks with Washington and was focused solely on defending the country.

Reporting from Tehran, Al Jazeera’s Resul Serdar said the latest escalation made a return to negotiations “extremely difficult”.

“There’s now a low-intensity war, new sanctions are back on Iran, and there’s a US blockade again,” Serdar said.

However, he said, “if the Americans commit to the articles of the memorandum of understanding, then the Iranians say they’re open to engaging diplomatically”.

Iran renews attacks on Gulf neighbours

On Wednesday morning, Iran’s Islamic Revolutionary Guard Corps said it targeted the US Fifth Fleet in Bahrain as part of a “crushing response”. It said it also targeted a major US military logistics hub in Mina Abdullah, Kuwait.

Kuwait’s Ministry of Defence said later on Wednesday that it had downed at least four cruise missiles and 21 drones from Iran throughout the day.

Jordan’s military said it had downed three missiles from Iran.

Gulf Cooperation Council Secretary-General Jasem AlBudaiwi condemned the latest “treacherous” Iranian attacks on Bahrain, Kuwait and Jordan, saying they “reveal Iran’s determination to drag the region into further chaos and instability”.

Zeidon Alkinani, founding director of the Arab Perspectives Institute, said that Iran’s continuing attacks on its neighbours had tested the patience of Gulf states, who oppose the US-Israel war on Iran and have staunchly advocated for diplomacy.

“The patience within the Gulf and the view of Iran may fall apart very soon,” Alkinani told Al Jazeera.

Trump says Iran ‘better behave’

US President Donald Trump warned on Tuesday that US attacks against Iran would intensify if the country’s leaders did not return to negotiations, even threatening to “knock out” Iran’s power plants and bridges.

But Trump declined to give Iran a firm deadline when asked on Wednesday, saying: “I don’t ⁠like giving deadlines, but ⁠they pretty ⁠much know; they ⁠know the story… they better ‌behave.”

Ghalibaf said Iran was still balancing diplomacy with military action in pursuit of its national interest.

While Iran has “never welcomed war… we must always be prepared for battle and stand firm to protect our national security and interests”, Ghalibaf said.

“We must also use the tools of diplomacy and negotiation to achieve and solidify our national interests.”