US warship Reagan in service

Reagan's wife Nancy attended the ceremony

The US Navy's newest aircraft carrier, the USS Ronald Reagan, has entered service.

It is the first US aircraft carrier to be named after a living former president.

However Ronald Reagan - now 92 and suffering from Alzheimer's disease - was not present at the commissioning ceremony in Norfolk, Virginia.

His wife, Nancy, who christened the ship in 2001, attended instead.

She was cheered wildly by the crowd when she walked to a podium and waved.

USS RONALD REAGAN 1,096 feet long (334 metres) Top speed: 30 knots Two nuclear reactors Can operate for 20 years without refuelling Carries more than 80 aircraft Home to 6,000 sailors Based in San Diego

"I only have one line, so 'man the ship and bring her to life," Mrs Reagan told the crew.

As the carrier's whistle sounded and the sailors ran aboard, two F-14 Tomcats and two F-18 Hornets flew overhead in formation.

In a speech at the ceremony, Vice-President Dick Cheney paid tribute to the former president's values and defence of freedom.

"In the lifetime of this carrier as in the lifetime of its namesake, enemies of freedom will fall away and the realm of freedom will expand further across the face of the Earth," he said.

The nuclear-powered USS Ronald Reagan replaces the USS Constellation in carrier fleet.

The US Navy announced in December that its next aircraft carrier would be named the USS George H W Bush after the former president.

There is also a nuclear-powered submarine called the Jimmy Carter and a naval cargo ship called the Bob Hope.