Donald Trump's war has escalated after Tehran retaliated by firing missiles and drones at war-weary US allies in the Middle East, while American strikes bombarded an Iranian nuclear plant.

A day after the President declared the ceasefire 'over' and struck more than 170 regime targets, Kuwait and Bahrain faced fresh Iranian attacks on Thursday morning.

Jordan, a US ally, said five Iranian ballistic missiles were fired from northwestern Iran toward an air base in the country, delaying flights across the region. 

Sirens could be heard blasting for civilians to take cover as all Iranian missiles were intercepted, the government says.

Iranian officials claimed that US military strikes sent shrapnel and projectiles slamming into the perimeter of the Bushehr nuclear power plant in southern Iran.

US strikes on Iran over the last 48 hours have targeted Iran's military assets near the Strait of Hormuz, a waterway responsible for one-fifth of the world's oil supply. 

Various Iranian air defense systems, drones, regime speed boats, and missile storage sites have been destroyed, according to US Central Command. US officials claim that the strikes are designed to stop Iran from attacking commercial shipping vessels crossing the strait.

Iran's Revolutionary Guard claims it has successfully struck US military bases near the Persian Gulf. The Daily Mail has contacted the Pentagon for comment. 

The chaos from the latest US-Iran strikes has delayed the final stage of the funeral procession for slain Supreme Leader Ayatollah Ali Khamenei, according to the New York Times. 

Hundreds of thousands of mourners in recent days have taken to the streets of Tehran to mourn the death of the country's notorious dictator. 

Khamenei was set to be buried in his hometown, the holy city of Mashhad, on Thursday, but the burial was delayed as strikes rang out nearby. 

Iranian state media also said a railway bridge in the Golestan province had been hit while the Revolutionary Guard reported two bridges had been attacked.

Explosions were also reported in several Gulf nations on Wednesday night, as Iran claimed it attacked US bases in neighboring countries in retaliation.

A spokesman for US Central Command said yesterday: 'US forces remain vigilant, lethal, and prepared to execute operations directed by the Commander in Chief.'

Trump had previewed potential strikes at a NATO summit in Ankara earlier on Wednesday.

'We're gonna hit 'em hard tonight. They violate the agreement every day,' he said.

Trump had said earlier in the day that the latest back-and-forth fighting would not result in 'long-term' military action.

'Anything that happens is going to happen very fast,' Trump said, though he also suggested the U.S. military might 'just finish the job.'

Trump also renewed his past threats to hit Iran's civilian infrastructure, including electric plants and desalination plants, and to seize the oil-production hub of Kharg Island.

The President's move against the regime follows a funeral eulogy for Khamenei in which a state-backed speaker openly called for Trump's death.