QINGDAO, China – China’s military opened its doors on Monday to U.S. Defense Secretary Chuck Hagel, offering America’s top defense official a rare look at its new aircraft carrier.

The two-hour visit was the first China has granted to a foreign official seeking a close view of the Liaoning, a refurbished Ukrainian ship that is the centerpiece of the county’s naval ambitions.

The U.S. ambassador to China, former Sen. Max Baucus, and top Pentagon officials joined Mr. Hagel on the tour during the defense secretary’s first visit to China since taking command at the Pentagon a year ago.

The visit provided American officials with a rare opportunity to assess the capabilities of the Liaoning and Chinese military development. Chinese officials compared their carrier development to the beginning of the American carrier fleet in the early 1900s, U.S. officials said.

“They know they have a long way to go in naval aviation,” said one defense official traveling with Mr. Hagel.

The official praised China for allowing Mr. Hagel to visit the ship as a milestone in military openness.

The tour came hours after Mr. Hagel delivered a pointed message to China about its relationship with its neighbors.

Over the weekend in Tokyo, Mr. Hagel chided China over its long-standing disputes with its neighbors over control of waters in islands in the East China Sea and South China Sea.

The Liaoning, named after the northeastern Chinese province where it is based, isn’t yet considered operationally effective. Pilots are still learning how to take off from and land on the aircraft carrier, and it lacks the full complement of technologically sophisticated support ships that characterize U.S. carrier groups.

Still, the Liaoning serves as a symbol of China’s regional ambitions and growing military might. In November, the Philippines warned that the Liaoning’s first training mission in the South China Sea could aggravate regional tensions.

A Chinese company purchased the carrier’s empty hull from Ukraine in 1998, and the refurbished carrier made its first sea trial under Chinese control in August 2011.