BEIJING, April 7 -- U.S. Defense Secretary Chuck Hagel Monday kicked off his first visit to China since taking office.

Describing his three-day trip as a journey to boost trust, openness and transparency between Beijing and Washington, Hagel said on Thursday in Honolulu that Chinese are his "friends," stressing the U.S. policy of "pivot to Asia" is "not a contain-China strategy."

Those words were certainly welcomed by Beijing. However, other messages sent by Hagel in the past few days seemed confusing and could not be easily interpreted as friendship gesture.

In an interview with Japan's Nikkei newspaper on Saturday, Hagel criticized China's air defense identification zone (ADIZ) over East China Sea as provocative and unilateral, laying misplaced blame on Beijing for rising tensions in one of the most geopolitically sensitive areas.

As the new defense secretary, Hagel has to be informed of some basic facts.

The establishment of ADIZ is a normal move, which conforms to the UN Charter and is aimed to ensure stability, while the escalating tension, in the first place, was ignited by Tokyo's illegal "nationalization" of China's Diaoyu Islands in 2012.

Since then, the nationalist government led by Japanese Prime Minister Shinzo Abe launched a political campaign -- peaked by his visit to the controversial Yasukuni Shrine -- to challenge China's bottom line.

In fact, the growing assertiveness of Japan could be partly attributed to the United States. Irresponsible remarks by some U.S. politicians have emboldened the rightist forces in Tokyo.

No doubt, China and America do have differences, but they have many more in common.

China sincerely hopes to establish a new type of major-country relations with the United States, featuring mutual respect and common prosperity, which is essential for China's peaceful development.

As the world's second- and first-largest economies, China and America have a shared interest in a stable environment to facilitate economic prosperity. Neither of them, nor the global economy, can afford confrontation or conflict.

In this regard, Hagel's stay in China is expected to offer a rare opportunity for the United States to clarify its "pivot to Asia" policy and assure its China friend of its intention, so as to strengthen mutual trust and understanding across the Pacific.

Now the ball is in Hagel's yard.