The US has again struck the Iranian oil hub of Kharg Island, according to a White House official.
The US hit military targets on the island, the official who spoke on condition of anonymity said on Tuesday.
The reported strikes came hours ahead of a deadline US President Donald Trump set for Iran to capitulate to his demands or face a major attack.
He said on Tuesday morning that a “whole civilization will die tonight” if Iran did not make a deal.
Mr Trump has threatened to deploy ground troops to seize critical oil infrastructure on the island, but experts warn such an operation would cost the lives of many US military members and would not be a decisive move to ending the war.
The US had earlier in the war struck several targets on the island, including air defences, a radar site, an airport and a hovercraft base, according to satellite analysis by the Institute for the Study of War and American Enterprise Institute’s Critical Threats Project.
Earlier on Tuesday, the semiofficial Mehr news agency put out a report saying there had been several explosions on Kharg Island, without elaborating.
Meanwhile, airstrikes hit two bridges and a train station in Iran on Tuesday, and Iranian officials urged young people to form human chains to protect power plants.
