TOKYO (Reuters) - U.S. Defense Secretary Chuck Hagel will visit China's sole aircraft carrier when he arrives in the country on Monday, a U.S. official said, in an unprecedented opening by Beijing to a potent symbol of its military buildup.
The official believed Hagel would be the first official visitor from outside China to be allowed on board the Liaoning, although that could not be immediately confirmed.
China's Defence Ministry did not immediately respond to a request for comment although Chinese state television noted Hagel would visit the ship. Chinese security experts said Beijing could be trying to quell U.S. criticism that it was not transparent about its military modernisation.
Hagel's planned carrier visit, which will come at the start of his three-day trip to China, was quietly approved by Beijing at Washington's request, the U.S. official said, speaking on condition of anonymity.
The 60,000-tonne Liaoning, a Soviet-era vessel bought from Ukraine in 1998 and re-fitted in a Chinese shipyard, is seen as a symbol of Beijing's growing naval power and ambition for greater global influence.
The carrier has yet to become fully operational, however, and military experts say it could be decades before China catches up to the far superior and larger U.S. carriers - if ever.
Hagel will fly to China's port city of Qingdao after a trip to Japan, and then head to a Chinese naval base. While there, he will visit the Liaoning, the U.S. official said.
Reporters travelling with Hagel were not expected to accompany him on the vessel, in what would also be a rare visit to a sensitive Chinese military site.
"It's a sign of openness, of sincerity, that China has nothing to hide and wants to improve military relations with the United States," said Ni Lexiong, a naval expert at the Shanghai University of Political Science and Law.
"It will also be a good opportunity for the Americans to see the difference between the Liaoning and their aircraft carriers," Ni said, referring to the technological gulf between the two countries.
CHINA GETS REGULAR ACCESS
Chinese military brass are no strangers to U.S. warships, including aircraft carriers.
Officers from the People's Liberation Army are routinely flown to U.S. aircraft carriers en route to occasional port stops in Hong Kong, according to U.S. military officials.
Their U.S. counterparts provide tours of the ship and flight deck during operations - efforts U.S. diplomats say are geared to nudging China towards greater transparency about its own capabilities.
Ian Storey, a Singapore-based regional security expert, said Hagel's visit would be "long on symbolism but short on actual operational capabilities".
"By showing him a vessel that was built in Ukraine in the 1980s and remains only a training platform that is still not fully operational, the Chinese will be keeping him away from their more sensitive capabilities, such as their missile programmes or submarine fleets," said Storey, of Singapore's Institute of South East Asian Studies.
China is building new submarines, surface ships and anti-ship ballistic missiles, and has tested emerging technology aimed at destroying missiles in mid-air.
The disclosure of the carrier visit came a day after Hagel said he would use his first trip to China as defense secretary to press Beijing to use its "great power" wisely and respect its neighbours, who have been put on edge by the country's growing assertiveness in Asia's disputed waters.
"Coercion, intimidation is a very deadly thing that leads only to conflict," he said at a news conference on Sunday at Japan's defence ministry.
China claims 90 percent of the 3.5 million sq km (1.35 million sq mile) South China Sea, which is believed to be rich in oil and gas. The Philippines, Vietnam, Malaysia, Brunei and Taiwan all claim parts of those waters.
Beijing has a separate dispute with Tokyo in the East China Sea over uninhabited islets that are administered by Japan. China's decision in November to declare an air defence identification zone in the area that includes those islands sparked protests from the United States, Japan and South Korea.
RISKS OF A MISHAP
Hagel, in his talks in Japan over the weekend and last week at a gathering of Southeast Asian defense chiefs in Hawaii, has sought to reassure allies of the U.S. security commitment to the region and has promised frank discussions in Beijing.
China, in turn, has repeatedly urged the United States not to take sides in any of these disputes, and has watched warily as Washington moves to strengthen its military alliances in the region, especially with Tokyo and Manila, as part of its strategic "pivot" toward Asia.
"Both sides are aware of the potential for military clashes, and the need to increase understanding and manage and reduce the risks, so this visit is a positive sign," said Zhu Feng, director of the International Security Programme at Peking University.
The risks of a mishap were highlighted in December when the American guided missile cruiser USS Cowpens had to take evasive action in the South China Sea to avoid hitting a Chinese warship operating in support of the Liaoning.
The Chinese carrier is the first step in what state media and some military experts believe will be China's deployment of several locally built carriers by 2020.
While President Xi Jinping recently urged China's military leadership to work faster to get the carrier combat-ready, some Chinese analysts and parts of the state media appear keen to dampen expectations about the Liaoning, which went on its first training mission into the South China Sea late last year.
The Liaoning would serve as a training platform rather than a fighting weapon, some Chinese experts have said.
Considerable doubt also remains over when it will be fully operational. Earlier estimates of two or three years had grown rubbery, with some hints internally that it could stretch to a decade, some experts say.
(Additional reporting by Ben Blanchard in Beijing and Greg Torode in Hong Kong; Editing by Dean Yates)