China's military chief is bluntly criticizing the United States for holding military exercises in the South China Sea and conducting surveillance flights off its shores.

General Chen Bingde made the remarks Monday at a joint press conference with his American counterpart, Admiral Mike Mullen. Chen said recent U.S. exercises with the Philippines and Vietnam are “extremely inappropriate” at a time when China is embroiled in tense territorial disputes with both countries.

Chen also charged after talks with Mullen that U.S. spy planes are flying within 25 kilometers of China's borders. He urged the United States to consider the feelings of the Chinese people.

Mullen, who is in China on a four-day visit, responded that the United States has been staging drills with its friends and allies in the region for decades and will continue to do so. He said the United States will also continue the surveillance flights, which are within “international norms.”

The official Xinhua news agency quoted Chen before the press conference saying he and Mullen had found “a lot of common ground” but had “different opinions on certain issues.”

Chen told Xinhua that apart from the South China Sea disputes, the two had discussed cyber security, China's military development and the attitude of some U.S. politicians toward China.

Mullen's visit to China is the first by a U.S. military chief of staff since 2007. He is returning a visit by Chen to the United States in May.

Mullen said after his arrival in Beijing Sunday that he is worried that China's disputes with the Philippines and Vietnam could spin out of control. The countries have competing claims to parts of the South China Sea believed to be rich in oil and gas.

China says the United States should stay out of the disputes, but Washington has reaffirmed its commitment to a mutual defense treaty with the Philippines. The United States has also declared a national interest in maintaining free navigation through the waterway, which carries vital sea traffic between Northeast Asia, and Europe and the Middle East.

Speaking Sunday at Beijing's prestigious Renmin University, Mullen said the United States is, and will remain, a Pacific power. But he said the regional and global challenges facing the U.S. and China are too large and too vital to be blocked by misunderstandings.