The pledge was contained in a government policy paper issued every two years and follows complaints from the United States and other countries that China hasn’t adequately explained the goals of its rapid military expansion in the last three decades.

Alarm bells have sounded over the detention of foreign fishermen and harassment of research vessels in the South China Sea, along with warnings to the U.S. to stay out of the Yellow Sea off its northern coast and aggressive maneuvering by Chinese ships and helicopters in waters near Japan.

Stronger assertions of sovereignty claims have also sparked a regional backlash, drawing China’s neighbors closer to rival Washington and posing new challenges to Chinese diplomacy.

In an apparent recognition of the need for greater communication, the defense report included for the first time a separate section on military confidence building, highlighting defense consultations, joint training missions and exchanges between border units.

China, the report stated, is pursuing such steps as "an effective way to maintain national security and development, and safeguard regional peace and stability."

Washington has urged increased contacts with the Chinese military, although the People’s Liberation Army has often appeared reluctant. Beijing cut off formal exchanges in anger at a $6.4 billion arms package offered to Taiwan last year, although the defense paper said the sides were now "maintaining effective dialogues and communications after various ups and downs."

The 2.3 million-member People’s Liberation Army is the world’s largest standing military and its modernization has been accompanied by gradual steps toward greater engagement with the outside world, including sending more than 17,000 military personnel to take part in United Nations peacekeeping missions.

Yet the PLA’s boosted capabilities and soaring budgets have also alarmed many observers concerned with challenges to the U.S. Navy’s predominance in the western Pacific. On the back of booming economic growth, China’s official defense spending rose 12.7 percent this year to about 601 billion yuan ($91.5 billion), second highest in the world behind the United States.

In introducing the report, Defense Ministry spokesman Geng Yansheng reasserted Chinese claims that it would never use its military might to bully its neighbors.

"At present and in future, no matter how developed China is, China will never seek hegemony or pursue expansionist policies," Geng said.

"China’s armed forces adopt a peaceful, cooperative and constructive approach in participating in international military affairs," he said.

Geng also repeated a vague pledge to hold military contacts and exchanges with Taiwan "at an appropriate time," in keeping with recent improvements in overall ties between the rivals. China regards Taiwan as a breakaway province and threatens to use force to block any Taiwanese bid for formal independence, backing that up with the deployment of more than 1,000 missiles targeting the island.

Strained relations between the U.S. and Chinese militaries improved slightly when U.S. Defense Secretary Robert Gates visited China in January. PLA chief of the general staff, Chen Bingde, is scheduled to travel to Washington in May.

At the same time, China has made significant gains toward fielding a missile system designed to sink a moving aircraft carrier from nearly 2,000 miles (3,200 kilometers) away, the U.S. military said earlier this year. The "carrier-killer" missile and a new showpiece stealth fighter jet may not be a match for U.S. systems, but they represent rapid advances for China’s homegrown technology and defense manufacturing. Chinese plans to launch up to five aircraft carriers in coming years have also altered strategic thinking in the region.

The defense paper repeated Chinese irritation with U.S. support for Taiwan. U.S. sales of armaments to the island were "severely impeding Sino-U.S. relations and impairing the peaceful development of cross-strait relations."

The report also highlighted China’s role in sending military ships to take an anti-piracy role in the Gulf of Aden off lawless Somalia.

The ships work alongside those from NATO nations, Russia and India, and are fighting piracy in the sea corridor between the Red Sea and the Indian Ocean that is one of the world’s busiest sea lanes. Chinese commercial ships have been among those hijacked and held for ransom by the pirates.