The nuclear-powered aircraft carrier USS George Washington suffered "serious" damage from a fire last month, Japanese media reports said Thursday.
The Nimitz-class vessel was expected to head for Japan's central Yokosuka port to replace the only remaining conventionally propelled carrier, USS Kitty Hawk, reported dpa.
But the arrival will be delayed at least until September from initially scheduled August due to damage repairs, Japan's Kyodo News Agency said.
The fire broke out on May 22 while the vessel was traveling in the Pacific Ocean off South America, damaging some of the ship's 3,800 compartments.
Steel walls of compartments on the carrier were found to have melted or become twisted in some sections due to the fire and there was serious damage to an aircraft elevator, Kyodo quoted sources as saying.
George Washington's deployment in Yokosuka port is drawing controversy in Japan over safety concerns posed by the ship's two nuclear reactors.
"US nuclear-powered warships have been operating safely for more than 50 years without a reactor incident or any release of radioactivity that has had an adverse affect on human health, marine life, or the quality of the environment," Lieutenant Sean Robertson, a Navy spokesman in Washington said.
The George Washington would be the first US nuclear-powered carrier to use a Japanese city as a home port.