United States President Donald Trump has said the US will not attack Iran before the November 3 midterm elections, dismissing speculation of imminent military action.

Trump made the announcement late on Thursday in a post on Truth Social. "We are having productive discussions with the Islamic Republic of Iran," he wrote. "We will not be attacking Iran at any time prior to the midterm elections to be held in the United States on November 3rd."

Oil prices fell early on Friday as Middle East supply concerns eased somewhat, after tensions in the energy-rich Gulf region had mounted in recent weeks.

The possibility of renewed fighting had appeared to drive up oil prices during Thursday's trading session. Some analysts believe Trump's comments were an attempt to bring prices back down.

Iran's Foreign Minister Abbas Araghchi said Tehran is reviewing the US response to its seven-day plan to reopen the Strait of Hormuz, and that Iran will respond within the "next few days." He added that negotiations are continuing through mediators, according to reports from Iran's Tasnim news agency.

Iranian media reported "massive explosions" in the southern Strait of Hormuz on Friday. Reports cited unnamed military sources as saying tankers using "unauthorised" routes may have struck sea mines.

On Tuesday, US Vice President JD Vance said Iran must make a "meaningful" reduction in its uranium enrichment capacity as part of any agreement to end the war. Experts say the demand may signal a softening of Washington's earlier insistence that Tehran abandon enrichment altogether.

On Monday, Iranian President Masoud Pezeshkian said negotiations with Washington were "futile," accusing the US of using talks as cover for continued military action against Iran.

Russian President Vladimir Putin told Pezeshkian that Russia will "do everything" to help end the US-led war on Iran, according to Russian news agencies, which reported the statement on Thursday.