The US also began a fresh round of strikes "to continue degrading Iranian capabilities used to attack commercial shipping in the Strait of Hormuz", the US military said.
Tehran says it has again closed the strait after hostilities between Iran and the US reignited last week, fraying an already fragile truce reached in June after several months of fighting that has killed thousands.
"I'll save the energy targets for last, but ultimately we'll hit energy targets," Trump told Fox News in an interview aired on Tuesday.
"Next week comes the power plants, next week comes the bridges, unless they get to the table and negotiate," Trump said.
US negotiators had been in touch with their Iranian counterparts to tell them "you better make a deal", he added.
Iran's army said early on Wednesday it had launched drone attacks against US positions at Jordan's Azraq base.
Iran's Islamic Revolutionary Guard Corps said they targeted weapons and storage facilities in Bahrain and Kuwait.
The flare-up over the last few days has heightened doubts that a memorandum of understanding signed last month would lead to a permanent halt to the war, which has engulfed Iran's neighbours and disrupted global energy supplies.
US American projectiles hit a location around Bandar Abbas, an Iranian city on the strait, the governor's office told state media late on Tuesday, while Iranian state news agency IRNA said US projectiles hit an area near Sirik in southern Iran.
"If the US thinks that by tightening its measures against us, its military actions and its economic blockade, we will return to negotiations, it is making a mistake," Iran's Deputy Foreign Minister Kazem Gharibabadi told state television.
Before the war began in February, about a fifth of global oil and gas shipments passed through the Strait of Hormuz.
The US said late on Tuesday that Iran had attacked seven commercial ships over the last week, leading to nearly a dozen crew members being killed, missing or injured.
The United Arab Emirates said earlier that one Indian crew member was killed and eight others were wounded when two Emirati oil tankers were struck by Iranian cruise missiles in the Strait of Hormuz.
The IRGC said two "offending" supertankers had been hit and disabled in the strait after ignoring repeated warnings.
They did not identify the vessels. As tensions escalated, Trump on Monday had floated the idea of a 20 per cent fee on shipping through the strait, which drew sharp criticism from the UN shipping agency and others.
On Tuesday, he scrapped the idea and said he would instead seek investment deals with Gulf states.
The naval blockade against vessels transiting to and from Iranian ports and coastal areas came back into effect at 2000 GMT (6am AEST Wednesday), after being lifted in June.
Trump said the strait was open to all shipping traffic except that of Iran.
There are currently more than 20 US Navy warships and hundreds of military aircraft operating across the region, the US military said.
The conflict has proved unpopular in the US, where gasoline prices have risen and congressional elections are looming in November.
The price of benchmark Brent crude oil is up 15 per cent over the last seven days to $US85 ($A122) a barrel, the highest since mid-June.
Iran said earlier on Tuesday that it attacked a US Army base in Jordan with ballistic missiles, while Bahrain, which hosts a US naval base, reported fending off an Iranian aerial attack and other Gulf states also came under fire.
The governor's office of Iran's Qeshm Island, on the Strait of Hormuz, said it was struck by a US projectile, Iranian state media reported.
Trump said certain countries, without naming them, had told him they wanted to invest in the US instead of being charged a transit fee.
It was not immediately clear what Gulf states had agreed to, if anything, and he did not mention any specific investment commitments.
