The USS Nimitz, one of the largest warships in the world, was ordered back to the Arabian Gulf last week, days before the killing of a prominent Iranian nuclear scientist, the US Navy said.
The USS Nimitz follows the rapid deployment of US Air Force B-52H Stratofortresses to the Gulf last Sunday to deter aggression and preserve stability. The navy said the deployment of the aircraft carrier was not related to any specific threat but was intended to ensure stability while US forces were withdrawn from Iraq and Afghanistan.
"There are no specific threats that prompted the return of the Nimitz combat group," said Rebecca Rebarich, spokeswoman for the US Fifth Fleet, which is based in Bahrain, after the aircraft carrier was sent to the Gulf on Wednesday.
"This act ensures that we have sufficient capacity to respond to any threat, and to deter any opponent from moving against our forces during the drawdown," Ms Rebarich said.
"The return of Nimitz is centred on maintaining Centcom's ability to remain postured and prepared to help preserve regional stability and security," Ms Rebarich said, referring to the US Central Command.
The Pentagon said that they would provide combat support and air cover with the withdrawal of thousands of American soldiers from Iraq and Afghanistan in mid-January, ordered by President Donald Trump.
About 2,000 troops will be pulled from Afghanistan and 500 from Iraq, leaving about 2,500 in each country.
In early October, the USS Nimitz left the Gulf after nearly two months in the region to join Australia, India and Japan in scheduled exercises in the Arabian Sea.
The Fifth Fleet's Twitter account showed pictures of the Nimitz's air wing on flight operations there on Saturday.
Carrier groups typically include a cruiser, a destroyer squadron and an air wing.
The USS Nimitz-class carriers are more than 304 metres long, have a crew of more than 6,000, and carry up to 90 helicopters and fixed-wing aircraft.
