China's first aircraft carrier was delivered and commissioned to the People's Liberation Army (PLA) Navy Tuesday after years of refitting and sea trials.

Overseen by President Hu Jintao and Premier Wen Jiabao, the carrier was officially handed over by the navy's main contractor, the China Shipbuilding Industry Corp., at a ceremony held at a naval base in northeast China's port city of Dalian.

President Hu, also Chairman of the Central Military Commission (CMC), endorsed a PLA flag and naming certificate to Senior Captain Zhang Zheng, commanding officer of China's first carrier, the Liaoning.

"Today will be forever remembered as China's Navy has entered an era of aircraft carrier," Zhang told Xinhua on the carrier's flight deck.

"When I received the PLA flag from the President, a strong sense of duty and commitment welled up in my heart," said Zhang who has served as commanding officer on the Navy's frigate and destroyer.

The carrier, rebuilt from the Soviet ship Varyag, was renamed Liaoning and underwent years of refitting efforts to install engines, weapons, as well as a year-long sea trial.

According to Mei Wen, political commissar of the carrier, the Liaoning will be operated by a well-educated and trained crew, as more than 98 percent of the commissioned officers on board hold bachelor degrees and more than 50 of them hold master or doctoral degrees.

Most of the carrier's commissioned and non-commissioned officers were selected and transferred from the Navy's other surface vessels through tough competition. Female sailors also serve at various posts on the Liaoning.

The Navy did not disclose any type of carrier-borne aircraft deployed on the Liaoning. But one maintenance officer in charge of the carrier's air wing said they would deal with engine noise and jet blast heat.

"The delivery and commission of the Liaoning is just a small step of China's aircraft carrier program and there is a long way to go before we have a powerful navy," said the commanding officer.

The delivery made China the tenth country and the last one of the five permanent members of the U.N. Security Council to have an aircraft carrier in active service.

An aircraft carrier has long been expected to join China's naval fleet to better protect territorial waters and overseas maritime interests.

Premier Wen said, in reading off a congratulatory letter sent from top central authorities, that China's first aircraft carrier in active service will "be of great and far-reaching significance in inspiring patriotism, national spirit and driving national defense technologies."

"The PLA's General Armament Department, the Navy and all comrades participating in the carrier program should make new contributions in promoting China's weaponry construction and safeguarding national sovereignty, security and territorial integrity," Wen said.

"The country and the people appreciate (the efforts of) all participants in the aircraft carrier program," Wen said.

After the commission ceremony, President Hu boarded the Liaoning, which was in full dress, and inspected the Navy's honor guard.

President Hu expressed his appreciation for the construction of the Liaoning and ordered the Navy and relevant research institutes to keep up their good work.

The president and the premier later came to the carrier's flight deck and some cabins where they talked with sailors, and scientists and engineers who developed the carrier.

"Developing an aircraft carrier was an important strategic decision made by the Communist Party of China (CPC) Central Committee, the State Council and the Central Military Commission," Wen said.

"It will also be of great significance in enhancing national defense power and the country's comprehensive strength," he said.

"The delivery and commission of the first carrier is a milestone in the PLA's history and embodies a major achievement of China's weaponry and equipment development, as well as its national defense modernization," Wen said.

Yin Zhuo, an information expert in the PLA Navy, said the carrier will not change the defensive nature of China's defense force.

"In modern warfare, small and medium-sized warships are increasingly insufficient to organize active defense for China with an increased strategic depth," said Cao Weidong, a researcher with the PLA Navy's military academic research institute.

"An aircraft carrier will give the Navy defense capacity far beyond land-based aviation force's combat radius," said Fang Bing, an associated professor with the PLA's National Defense University.

As a weapon, an aircraft carrier can be used for both defense and offense, and it can also be used for humanitarian purposes, Fang said. He added that during the World War II, aircraft carrier groups were used for the purpose of invasion by the Japanese, but for anti-invasion warfare by the allied forces.

The delivery and commission ceremony came on the same day when the Chinese government released a white paper on the Diaoyu Islands which asserts the islands in the East China Sea "an inherent territory of China".

Fang said he did not believe that the commission of the Liaoning was specifically related to China's current dispute with Japan over the Diaoyu Islands. But he said China has zero tolerance to foreign infringement of the country's territorial waters, with or without an aircraft carrier.

According to the CMC, after being commissioned to the Navy, the Liaoning will continue to serve for scientific research purposes, as well as military training.

Hu and Wen were accompanied by CMC Vice Chairmen Guo Boxiong and Xu Caihou, as well as State Council Secretary-General Ma Kai, director of the PLA's General Armament Department Chang Wanquan and Navy Commander Wu Shengli.

China announced its aircraft carrier program in July 2011, when the carrier was berthed in Dalian for refitting. Dalian is located at the south end of Liaoning Province.

(CNTV.cn, Xinhua News Agency September 25, 2012)