BEIJING, Jan 11 (AP) -- Chinese officials have called for stronger ties with the United States, but warned Washington against interfering with Taiwan's relations with the mainland, state media reported Wednesday.

Minister of National Defense Cao Gangchun told a visiting delegation from the U.S. Congress, on Tuesday that Beijing wanted to deepen military ties with Washington so as to better reflect their political relationship, the official Xinhua News Agency said.

Military contacts were cut off following the collision of a U.S. Navy surveillance plane with a Chinese fighter jet in 2001 but have warmed over the past two years.

Washington has also called on Beijing to show more transparency in its military build up, especially in the reach of its nuclear missiles.

"We are glad to see our military ties gradually resume and develop in recent years with joint efforts on both sides," Cao was quoted as saying by Xinhua.

In his meetings with the congressional U.S.-China Working Group, Cao repeated warnings that the United States should stay out of a dispute over the future of Taiwan, which split from the mainland amid civil war in 1949.

Beijing's Communist leaders have maintained that the island -- with its democratically elected government _ remains a part of China and has threatened to invade if it makes its de facto independence permanent.

According to Xinhua, Cao said he hoped Washington would abide by its commitment to seek a peaceful resolution of the Taiwan issue.

Cao, also vice chairman of the powerful Central Military Commission, attributed the thaw in relations in part to a visit by U.S. Defense Secretary Donald H. Rumsfeld to China last year.

"His visit played a positive role in strengthening mutual understanding and cementing our military ties," Cao said.

China was ready to expand military exchanges with the United States, but did not offer any suggestions, Cao said.

Washington considers military ties a key part of diplomatic relations and has said it would like to hold joint search-and-rescue exercises with China. Chinese officers, however, are believed to be wary of any joint operations with their potential rivals.

The two sides have allowed port calls by each other's naval warships.

Senior Chinese legislator Wu Bangguo delivered the same message on Taiwan to the working group, led by Representatives Mark Kirk, a Republican from Illinois and Rick Larsen, a Democrat from Washington.

Wu also praised exchanges between the Chinese and U.S. legislatures, saying they were an important part of improving understanding between the two countries.

He said that as long as China and the United States continued to communicate on various levels, relations between the two countries would improve.