LOS ANGELES (Reuters) - Defying the Clinton administration and China, a U.S. lawmaker said Monday he met with Taiwan's President Chen Shui-bian during a U.S. transit stop, telling him he had broad support in the United States and urging him to be ''strong'' in the face of challenges from Beijing. Making a 15-hour stopover in Los Angeles before flying on to the Caribbean and Central America on his first foreign tour, Chen was to spend the night at a Long Beach hotel amid security so tight that he was hustled away from 500 cheering supporters carrying his photograph and signs saying ``We Love You.'' Before leaving Taipei for a trip aimed at staving off Beijing's attempt to woo Taiwan's diplomatic allies, officials said Chen would keep a low profile during his transit stop to avoid embarrassing Washington, which has persuaded him not to meet a small bipartisan group of U.S. politicians.

Beijing has already vented its fury over Washington's permission for Chen's stopover en route to Central America, calling it a breach of U.S. promises not to have official contacts with Taipei. Undeterred, California Republican Representative Dana Rohrabacher, one of the most vocal critics of China in Congress, went to Chen's hotel and held what he called a brief ''personal'' meeting with the president.

``I would have to catalog it not as an official meeting,'' Rohrabacher told Reuters afterward. ``It was a greeting from a friend. I went to wish him luck and to tell him that he has in the United States a great deal of support and that he should be strong.'' The State Department granted a transit visa to Chen's entourage for the trip that precluded the Taiwanese president, who was elected in March, from engaging in any public activities in the United States.

Washington, which switched formal diplomatic relations from Taipei to Beijing in 1979 as part of a ``one China'' policy, was clearly eager to avoid an embarrassing repeat of a 1995 incident in which it granted a visa to former Taiwanese President Lee Teng-Hui for a ``private'' visit to his alma mater, Cornell University in New York. Lee's visit prompted Beijing to withdraw its ambassador to Washington in protest and set off escalating tensions between China and Taiwan, with China eventually firing missiles across the Taiwan Strait.

Beijing regards Taiwan as a renegade province. It strongly protested the U.S. decision to grant Chen even a transit visa. Despite the warnings, Rohrabacher, a vocal supporter of Taiwan, said he ``just went to (Chen's) hotel to talk, one friend to another.'' ``I thought it was symbolically important to demonstrate that we respect this man, who has been elected by Taiwan, and that we should not refrain from doing so to placate un-elected people at home and abroad,'' the congressman said.

Administration officials feared any meetings with Chen in the United States would spark a backlash from Beijing and undermine fragile support in the U.S. Congress for increasing commercial ties with China.

The U.S. Senate is expected to vote in September on legislation that would grant permanent normal trade relations (PNTR) to China, ending the annual ritual of reviewing Beijing's trade status and guaranteeing Chinese goods the same low-tariff access to U.S. markets as the products of nearly every other nation.

Some lawmakers have also proposed legislation that would increase U.S. military ties with Taiwan, over objections from Beijing and the Clinton administration.