China's drive to build a blue-water navy is a must as the country's national power is rising and interests extending, an expert said Tuesday as a white paper underlined the development strategy of the navy.

In line with the requirements of China's offshore defense strategy, the People's Liberation Army Navy (PLAN) endeavors to accelerate the modernization of its forces for comprehensive offshore operations, said the white paper on China's armed forces.

It also develops blue-water capabilities of conducting mobile operations, carrying out international cooperation, and countering non-traditional security threats, said the document issued by the State Council Information Office.

It is the first time that China has clearly defined requirements for the navy's capabilities in blue waters.

Since its establishment six decades ago, the country's navy has gone through stages of coastal defense, inshore defense and offshore defense. In the new century, it is a must-taken road for the navy to go to blue waters, said Xiong Yuxiang, a research fellow with the Academy of Military Science.

The transformation is a response to the increasing complexity and instability of China's maritime security, he said.

A blue-water navy is also important to safeguard the country's extending national interests which are increasingly dependent on seas and oceans, he said.

As China is more engaged in the world economy, its foreign trade and investment is mainly realized through maritime transportation, Xiong said. "The armed forces will provide guarantees to national interests and citizens wherever they reach."

To protect national interests and fulfill its international obligations, the Chinese navy carries out regular escort missions in the Gulf of Aden and waters off Somalia. In September 2012, China's first aircraft carrier Liaoning was commissioned into the PLAN.

The navy also steps up regular training in blue waters. It organized seven batches of blue-water training in 2012 and another two batches this year. From April to September 2012, the training vessel "Zhenghe" completed a global-voyage training exercise.