(Yonhap) -- U.S. Secretary of Defense Chuck Hagel arrived in China's eastern port city of Qingdao on Monday, beginning his three-day visit to China for discussions on global and regional security issues, including North Korea's nuclear programs.

China is Hagel's third stop on his 10-day trip across the Asia-Pacific and his first visit to Beijing as the U.S. defense chief.

The trip comes at a time when regional tensions have been growing amid the North's threat of a fresh nuclear test and growing rivalry between Beijing and Tokyo.

In Qingdao, Hagel toured China's first aircraft carrier, the Liaoning, which was commissioned in 2012 as a symbol of China's growing military might, according to U.S. officials.

Russia's annexation of Ukraine's Crimean Peninsula, which showed that power matters less than commitment as Russia was more committed to the cause than the more powerful U.S., has also raised concerns over security among Asian nations.

In Tokyo, Hagel warned China against taking unilateral actions in territorial disputes with its neighbors.

"All nations, all people, deserve respect no matter how large or how small. I think we're seeing clear evidence of a lack of respect, along with intimidation and coercion in Europe today in what the Russians have done in Ukraine," Hagel said.

North Korea has threatened to carry out a "new form" of nuclear test after the United Nations Security Council condemned its latest missile launches.

Tension on the divided Korean Peninsula has risen significantly last week after North Korea conducted a live-fire drill near the tense Yellow Sea border. About 100 North Korean artillery shells fell in South Korean waters, prompting the South to return fire.

North Korea did not elaborate, but outside experts suspect that the "new form" of nuclear test may be based on enriched uranium.

The North has so far conducted three nuclear tests widely believed to be based on plutonium.

Japan has reportedly ordered its military to shoot down any North Korean ballistic missile that could hit the country.

In response to the North's latest belligerence, Hagel said Sunday that the U.S. will send two more Aegis-equipped warships to Japan by 2017.

"In response to Pyongyang's pattern of provocative and destabilizing actions, including recent missile launches in violation of U.N. Security Council resolutions, I can announce today that the United States is planning to forward-deploy two additional Aegis ballistic missile defense ships to Japan by 2017," Hagel said.

Shortly before Hagel arrived in Qingdao, China's state-run Xinhua News Agency published a commentary voicing some dissatisfaction with remarks by the U.S. defense chief in Japan.

Xinhua said some "messages sent by Hagel in the past few days seemed confusing and could not be easily interpreted as friendship gesture."

Referring to criticism by Hagel of China's declaration of an air defense identification zone over the East China Sea, the commentary accused the U.S. defense chief of "laying misplaced blame on Beijing for rising tensions in one of the most geopolitically sensitive areas."