On Tuesday, Trump threatened to target Iran's energy infrastructure if Tehran failed to return to talks.
Iran's top negotiator, Mohammad Bagher Ghalibaf, told state media Tehran had "no reason" to abide by any agreement that did not benefit the country.
He added that Iran's national security depended on maintaining what he described as "Iranian arrangements" in the Strait of Hormuz.
In the latest attacks, the US targeted command centres, air defence sites, and coastal surveillance facilities across Iran - including in the port city of Bandar Abbas and Greater Tunb Island - US Central Command (Centcom) said.
Explosions were heard across Iran and air defences were triggered in Tehran, Iranian state media reported.
Shortly after, US allies in the Gulf reported attacks - Kuwait's military said it intercepted drone attacks, while Bahrain's interior ministry told citizens to remain calm and head to the nearest safe place.
The Iranian military also said it targeted US communication systems and fuel storage facilities in Jordan in its latest round of strikes.
Separately, the US fired on and disabled an unladen, Curacao-flagged oil tanker on Wednesday, which Centcom said was attempting to sail toward a blockaded Iranian port.
