Tuesday's talks with oil executives followed a deadlock in efforts to resolve the conflict, which has led the United States to try to squeeze Iran's oil exports with a naval blockade aimed at forcing it to reopen the Strait to shipping.
The US president has said Iran can call if it wants to talk and, in a post on Truth Social on Wednesday before details of the meeting emerged, said Iran "couldn't get its act together".
"They don't know how to sign a non-nuclear deal. They'd better get smart soon!" Trump said in the social media post, without explaining what such a deal would entail.
The post featured a mock-up image of him wearing dark glasses and wielding a machine gun, captioned, "No more Mr. Nice Guy."
The president and the oil executives "discussed the steps President Trump has taken to alleviate global oil markets and steps we could take to continue the current blockade for months if needed and minimise impact on American consumers," the White House official said.
Oil prices rose more than six per cent on Wednesday, with the Brent contract hitting a one-month high on prospects of a lengthy blockade.
The war has cost the US military $US25 billion so far, a senior Pentagon official said, providing the first official estimate of the price tag for the conflict.
Iran has pledged to continue disrupting traffic through the Strait as long as it is threatened, which may mean more Middle East oil supply disruptions from a conflict that has killed thousands and brought global economic upheaval.
With talks stalled, Trump is set to receive a briefing on Thursday on new plans for potential military action from the leader of the US Central Command, Brad Cooper, Axios said.
Tehran warned on Wednesday of "unprecedented military action" against continued US blockading of Iran-linked vessels. Trump has said Iran cannot have a nuclear weapon, while Tehran says its nuclear ambitions are peaceful.
The United States is asking other countries to join a new international coalition that would enable ships to navigate the Strait of Hormuz after traffic through the waterway stalled, according to an internal State Dept cable seen by Reuters.
The proposed coalition, dubbed the "Maritime Freedom Construct", would share information, co-ordinate diplomatically and help enforce sanctions, the cable showed.
France, Britain and other countries have held talks on contributing to such a coalition but said they are only willing to help open the Strait, a chokepoint for global energy supplies, after hostilities cease.
Iran's parliament speaker and top negotiator, Mohammad Baqer Qalibaf, said Trump was trying to divide Iranians and force Iran to surrender through the blockade.
"The solution for confronting the enemy's new conspiracy is only one thing: maintaining unity, which has been the bane of all the enemy's conspiracies," Qalibaf said in an audio message on messaging app Telegram.
Iran has executed at least 21 people since the start of the war with the United States and Israel two months ago, and arrested more than 4,000 on charges related to national security, UN human rights chief Volker Turk said.
In a sign of the toll the war is taking on Iran's economy, its currency fell to a record low on Wednesday, the Iranian Students' News Agency said. Inflation stood at 65.8 per cent for the month to April 20, the central bank said.
Iran's latest offer for resolving the war, suspended since April 8 under a ceasefire deal, would set aside discussion of its nuclear program until the conflict is formally ended and shipping issues resolved.
