"The USS Kearsarge and the USS Ponce entered the Suez Canal from the southern entrance at 6:00 am (0400 GMT) and are making their way to the Mediterranean sea," a canal authority official said.
On average it takes 12 to 14 hours for a ship to transit the canal.
The Kearsarge amphibious ready group, with about 800 marines, a fleet of helicopters and medical facilities, could support humanitarian efforts as well as military operations.
"We're certainly moving assets to be closer (to Libya)," a US defence official told AFP in Washington on Tuesday. "A ship like the Kearsage is capable of many types of missions."
Western powers are arguing over imposing a proposed no-fly zone over Libya to support rebels fighting Gaddafi's regime. Some opposition figures in Libya have begun calling for air strikes.
An American aircraft carrier, the USS Enterprise -- which has fighter jets that could enforce a possible no-fly zone -- could also be called upon for the Libya crisis.
The carrier is currently in the north of the Red Sea, according to the US Navy's website.