Amid tensions over Iran and Syria, the United States has brought forward the deployment of an aircraft carrier to the Middle East to shorten the time when a sole carrier is in the region.
Pentagon spokesman George Little told reporters on Monday that Defense Secretary Leon Panetta last week approved a request for the USS John-Stennis strike group to be deployed four months earlier than scheduled.
"It will now deploy in late summer. The decision will help support existing naval force requirements in the Middle East and will reduce the gap created by the planned upcoming departure of the Enterprise strike group," Little said.
There have been two aircraft carriers deployed in the region: the USS Abraham Lincoln and the USS Enterprise.
The Lincoln passed through the Suez Canal on Monday, leaving the Fifth Fleet's zone of responsibility en route back to the United States to complete its eight month deployment, the Pentagon said.
The Lincoln is to be replaced soon by the USS Dwight Eisenhower, which would have been left alone in the troubled Middle East region for several months had the US Navy not decided to accelerate the arrival of the Stennis.
The United States beefed up its presence in the strategic Gulf in December after Iran threatened to close the Strait of Hormuz if Western countries boycotted Iranian oil exports.
About one-fifth of the world's traded oil passes through the strategic waterway.
Little said the decision to speed the Stennis's deployment was a result of insecurity in the region -- including "challenges" posed by Iran.
"It's no secret that the United States and our partners and our allies in the region face serious challenges, from a variety of sources," he said.
"Syria is obviously a top national security priority for the United States but I won't get into whether or not these requirements as defined by Centcom are attached to the crisis in Syria."