The United States is deploying a carrier strike group and a bomber task force to the Middle East to send a clear message to Iran that any attack on US interests or its allies will be met with “unrelenting force”, US national security adviser John Bolton says.

Amid rising tensions between the US and Iran, Bolton said the decision was “in response to a number of troubling and escalatory indications and warnings”.

“The United States is not seeking war with the Iranian regime, but we are fully prepared to respond to any attack, whether by proxy, the Islamic Revolutionary Guard Corps or regular Iranian forces,” Mr Bolton said.

It marked the latest in a series of moves by US President Donald Trump’s administration against Iran in recent weeks.

Washington has said it will stop waivers for countries buying Iranian oil, in an attempt to reduce Iran’s oil exports to zero. It has also blacklisted Iran’s elite Revolutionary Guard Corps.

The Trump administration’s efforts to impose political and economic isolation on Tehran began last year when it unilaterally withdrew from the nuclear deal it and other world powers negotiated with Iran in 2015.

“The United States is deploying the USS Abraham Lincoln Carrier Strike Group and a bomber task force to the US Central Command region to send a clear and unmistakable message to the Iranian regime that any attack on United States interests or on those of our allies will be met with unrelenting force,” Mr Bolton said.

Mr Bolton, who has spearheaded an increasingly hawkish US policy on Iran, did not provide any other details.

A US official said the forces “have been ordered to the region as a deterrence to what has been seen as potential preparations by Iranian forces and its proxies that may indicate possible attacks on US forces in the region.”

The official, speaking on the condition of anonymity, said the United States was not expecting any imminent attack on its forces.

-AAP