BEIJING, NOV. 14 -- The first U.S. congressional delegation to visit China in more than a year has warned top Chinese leaders that their failure to release more political prisoners will jeopardize Beijing's most-favored-nation trading status with the United States, members said today.

"Our primary mission was to let them know that in the U.S. Congress, there is a linkage between the future of bilateral trade and a final resolution of Tiananmen Square," said Rep. John J. Rhodes III (R-Ariz.), referring to the government's massacre of demonstrators for democracy in central Beijing in June 1989.

The House voted in October to deny most-favored-nation trading benefits to China and to impose tough human-rights conditions on any extension of these benefits. The Senate failed to act on the bill, but the issue is likely to be raised when Congress convenes early next year, the members said. The trading status grants the lowest possible U.S. tariffs on a nation's exports to the United States.

The bipartisan group is the first U.S. congressional delegation to visit China since the crushing of the democracy movement by Chinese troops. The United States and other Western countries imposed sanctions against China to protest the crackdown, but largely as a result of China's cooperation in imposing sanctions against Iraq because of its invasion of Kuwait, Western countries have lifted the sanctions. The visit is the latest sign of the gradual improvement in the West's ties with China in the last several months.

The group, led by Rep. Michael G. Oxley (R-Ohio), met with Premier Li Peng Tuesday. State-run television showed Li warmly greeting the delegation in the opening report on the Tuesday evening news. Other members of the group are Rep. George Darden (D-Ga.), Rep. Jim Lightfoot (R-Iowa) and Rep. Clay E. Shaw Jr. (R-Fla.).

In their meetings with Li and other officials, the members said they urged the Chinese to release the 300 to 400 prisoners the Chinese government says are still jailed in connection with last year's protests. Li implied that the cases of many of those jailed would be resolved quickly, three members of the delegation said. Two other members of the delegation disputed that interpretation.

According to other officials who attended the meeting, Li said it was likely that more people would be released as the political situation in China stabilizes. "He didn't make any concrete commitment," said one U.S. official.

In discussions on the Persian Gulf crisis, Li made clear that China, one of the five permanent members of the U.N. Security Council, would not deploy troops to the Persian Gulf under any circumstances, the lawmakers said.