The United States has reportedly carried out military strikes on Iran's Qeshm Island, even as President Donald Trump signalled progress in negotiations with Tehran aimed at ending the eight-month-old conflict.

The strikes, described by US officials as "defensive," are said to be part of a series of limited operations Washington has quietly conducted in recent weeks.

Several explosions were heard on Qeshm Island late on Monday, according to Iran's state-owned news agency IRNA. Witnesses told the agency they saw two planes flying over the island, which lies off Iran's southern coast near the Strait of Hormuz.

Explosions were also reported in the port city of Bandar Lengeh, with the semi-official Fars news agency saying the blasts appeared to come from the direction of the sea.

US officials, cited by sources, said the military had carried out the strikes. Some officials described them as defensive, aimed at restricting Iran's ability to attack commercial shipping in the Strait of Hormuz.

One official said the US had deliberately kept the campaign quiet to avoid signalling a return to major combat operations.

A separate US official, cited by another source, confirmed that the US had conducted defensive strikes against Iranian targets in the Strait of Hormuz.

The strikes came as diplomatic activity between Washington and Tehran continued. Iran's foreign minister described recent US outreach as a "positive step," while the country's security chief said a US letter signalled a "positive" shift in tone.