Washington and Tehran struck a preliminary deal to end the war in June, but the agreement unravelled within a month of its signing.
At least 50 people have been killed and more than 500 injured in US strikes over the past three weeks, Iranian state media reported citing the country’s health ministry.
Thousands more have been killed across the Middle East since the US-Israeli war with Iran began on 28 February, official figures show.
Friday marked a seventh consecutive night of US strikes on Iran, according to the military – a week which also saw the US reimpose a blockade on Iranian ports and Tehran strike US allies in the Gulf, including Jordan, and declare the Strait of Hormuz closed.
As well as military targets, both parties have been accused of striking critical infrastructure in recent days.
The US denied Iranian accusations that it had hit bridges, a train station and an airport earlier this week. Washington said it had exclusively struck military targets. BBC Verify confirmed an attack on a bridge in Hormozgan province.
Trump had threatened on Tuesday to strike Iran’s bridges and power plants next week if the country did not return to talks.
Meanwhile, the Gulf Cooperation Council accused Tehran of deliberately targeting civilian infrastructure in the region. After Iran said it had responded to US strikes by targeting American Gulf allies on Saturday, Kuwait said a power plant and a water distillation plant had been hit.
Jasem Mohamed Albudaiwi, who leads the council representing Saudi Arabia, Kuwait, Qatar, Bahrain, the United Arab Emirates and Oman, said such action amounted to “war crimes”.
Under international law, attacking civilians or civilian areas is illegal. However, in certain circumstances, civilian objects – like a bridge or a power plant – lose their protection if they are used to support the enemy’s war effort.
Late on Saturday in Iran, its Supreme Leader Mojtaba Khamenei said in a written statement that America’s “repeated breaches” of the agreement had “laid bare a fundamental truth: the signature of the US president is utterly worthless and devoid of credibility”.
Khamenei has not been seen in public since the attack which killed his father, the previous ayatollah, at the start of the war.
