US President Donald Trump said Washington held talks with Tehran on Tuesday and urged Iran to negotiate an end to the conflict.

In an interview with Fox News, Trump warned that US military action would intensify if no agreement is reached. He said Iran could face attacks on key infrastructure, including power plants and bridges.

"Next week it gets really bad for them because next week comes the power plants. Next week comes the bridges," Trump said.

He added: "We're going to knock out all their power plants. We're going to knock out all their bridges unless they get to the table and negotiate."

When asked how long the US strikes would carry on, Trump said "they'll continue until I say it's enough."

The remarks come as US forces continue military operations against Iran and Washington enforces a renewed naval blockade on Iranian ports.

US completes new wave of strikes on Iran
The US military said it completed another round of strikes against Iran, targeting dozens of military sites near the Strait of Hormuz and along Iran's southern coast.

US Central Command, or CENTCOM, said fighter jets, drones and naval vessels took part in the seven-hour operation, hitting missile and drone sites, naval assets and coastal defense systems.

According to CENTCOM, the strikes were intended to further reduce Iran's ability to threaten commercial shipping and civilian crews in the region.

The attacks took place on the same day that the United States reinstated its naval blockade on vessels travelling to and from Iranian ports.

US Central Command added that American forces remain ready to carry out further operations if ordered.