Almost five weeks after it started with a joint US-Israeli aerial assault, the war in Iran continues to spread chaos across the region and roil financial markets, raising the pressure on Trump to find a quick resolution to the conflict.
Trump has stepped up his rhetoric as negotiations conducted via intermediaries with new leaders in Iran show limited signs of progress and pessimism at home about the war grows.
The US military "hasn't even started destroying what's left in Iran. Bridges next, then Electric Power Plants," Trump wrote on social media late on Thursday, adding that Iran's leadership "knows what has to be done, and has to be done, FAST!"
He earlier posted video of the US bombing a newly constructed bridge between Tehran and nearby Karaj.
According to Iran's state media, eight people were killed and 95 others were wounded in the US attack.
"Striking civilian structures, including unfinished bridges, will not compel Iranians to surrender," Iran Foreign Minister Abbas Araqchi said in a statement.
Satellite images also showed smoke rising from the port in Qeshm, an Iranian island in the Strait of Hormuz, earlier this week.
Still, Iran and its allies continue to strike targets around the Gulf.
Kuwait Petroleum Corporation's Mina al-Ahmadi refinery was hit by drones, setting off fires at operating units, but no injuries were reported.
Saudi Arabia's defence ministry said on Friday its air defences intercepted seven drones in recent hours.
An Iranian military spokesman said on Friday that a second US F-35 fighter jet was shot down over central Iran by Revolutionary Guard air defences, with low chances of pilot survival.
More than 100 American international law experts said on Thursday the conduct of US forces and statements by senior US officials raised serious concerns about violations of international law, including potential war crimes.
A letter signed by the experts particularly noted a mid-March comment from Trump where he said the US might conduct strikes on Iran "just for fun".
In a speech on Wednesday night, Trump repeated his threats against Iran's civilian power plants and gave no clear timeline for ending hostilities.
That drew vows of retaliation from Iran, weighed on global share prices and sent oil prices surging on concerns the Strait of Hormuz would remain largely closed.
Trump has expressed his frustration with his allies in NATO and elsewhere for not joining his war, this week telling countries that relied on fuel shipments through the strait to "just grab it".
Britain chaired a virtual meeting on Thursday of some 40 countries to explore ways to restore freedom of navigation that did not produce any specific agreement, although participants agreed that all nations should be able to use the waterway freely.
The UN Security Council is set to vote on Saturday on a Bahraini resolution to protect commercial shipping in and around the strait, but veto-wielding China made clear its opposition to authorising any use of force.
Iran has effectively shut down the strait, which usually carries about a fifth of the world's total oil trade, in retaliation for US-Israeli attacks that began on February 28.
Tehran offered a competing vision for future control of the strait, and said it was drafting a protocol with neighbouring Oman that would require ships to obtain permits and licences.
The European Union's foreign policy chief Kaja Kallas pushed back against Tehran's plan, saying Iran could not be allowed to charge countries a bounty to let ships pass.
