"In response to a number of troubling and escalatory indications and warnings, the United States is deploying the USS Abraham Lincoln Carrier Strike Group and a bomber task force to the US Central Command region," Bolton said in a statement.

The deployment is aimed at sending "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," Bolton said.

"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."

The USS Abraham Lincoln has previously been deployed to the Gulf, including during the 2003 US-led invasion of Iraq.

The statement did not specifically state why the deployment is taking place now, but Secretary of State Mike Pompeo later said it was not related to Gaza, where Palestinian militants and Israel have traded a barrage of rocket fire and air strikes in recent days.

"It is absolutely the case that we have seen escalatory actions from the Iranians and it is equally the case that we will hold the Iranians accountable for attacks on American interests," Pompeo said.

"If these actions take place, if they do by some third-party proxy, a militia group, Hezbollah, we will hold the Iranian leadership directly accountable for that," the chief US diplomat said before leaving on a trip to Finland.

Pompeo did not elaborate on what Iranian "escalatory actions" he was referring to.

The deployment comes amid heightened tensions between Washington and Tehran over the latter's nuclear program, with the US taking aim at Iranian enriched uranium exports with sanctions.

The US unilaterally withdrew from the 2015 Iran nuclear deal with world powers a year ago and instead vowed "maximum pressure" aimed at curbing the regional role of Iran, an arch-rival of US allies Saudi Arabia and Israel.

In April, the US also declared Iran's elite Revolutionary Guards a "foreign terrorist organisation."