The vessel is due to replace the USS George Washington, but both ships could remain in the region in the event of a conflict.
The deployment is the latest part of a growing military build-up in the Gulf, where up to five aircraft carriers could be in place by the end of the year.
It came as US media reported that the Pentagon plans to call-up thousands of reservists in the next few days to fill key military posts should war break out with Iraq.
There was tight security as the carrier group prepared to leave its port at Norfolk, Virginia.
About 100 relatives and friends gave a tearful farewell as sailors boarded the vessel.
Among them was Kik Hunter, whose boyfriend Yeoman Eric Micolichek was one of the Truman's 8,000 crew.
"I love him and I want to be here in six months when he comes back," she said, wiping rain and tears from her face.
While the deployment was a scheduled trip, the sailors knew they might be called on for active duty.
"It's our normal rotation, but we know it's pretty heated over there," said Petty Officer Hubie Linker.
"Everybody hopes it calms down, but that depends on [Iraqi President] Saddam [Hussein]," he said.
Captain Michael Groothousen, Commanding Officer of the Truman, said the crew was well prepared in the event of a war.
He said Saddam Hussein was "a thorn in our side".
"Nobody wants to go to war, especially soldiers and sailors, but when we're called upon, we're ready to go," he said.
Call-up
The New York Times newspaper reported that up to 10,000 reservists will be mobilised for security duty in the next few days.
The call-up is likely to be the first of a series of mobilisations.
"Activating reserves is significant because it will affect every community in America, and it sends a signal that the president is serious," the newspaper quoted a military official as saying.
The latest call-up will comprise mainly military police units, the Times said.
More than 50,000 reservists have been mobilised since the 11 September 2001 attacks on the United States, the newspaper reported.