The postponement of an anticipated visit to China by U.S. Navy ships, confirmed by the State Department yesterday, represents a symbolic setback for U.S.-China relations at a time when symbolism is important.

State Department officials said a visit was still under consideration and overall U.S.-Chinese relations were still on track. "Obviously, we've hit a snag," said one State Department official yesterday, answering queries about the visit to Shanghai.

At the regular noon briefing yesterday, State Department spokesman Edward Djerejian said that ship visits to China remain under consideration but that both sides are still discussing "a number of issues" through diplomatic channels.

Other officials said one of the key issues was the U.S. refusal to confirm or deny the presence of nuclear weapons aboard U.S. ships. This issue became an embarrassment to Peking and Washington after Hu Yaobang, the Chinese Communist Party leader, and a high-ranking Chinese Foreign Ministry official made remarks last month to Australian and New Zealand journalists that seemed to rule out the possibility of any nuclear-armed U.S. ships participating in port calls.

The two sides apparently had difficulty agreeing on how to desribe the port call in a way in which each side could show it was sticking to its previous public positions.

"The whole problem has been to agree on language that would get Hu's foot out of his mouth," said one diplomat involved with this issue.

Djerejian made a special point yesterday of repeating that the United States would maintain its worldwide policy of neither confirming nor denying whether U.S. ships carry nuclear weapons.

"We hope that after a bit of time passes, we can arrange a port visit," said a State Department official.

Other western nations have sent ships to China on goodwill visits in recent years, and the idea of having the United States send its ships on such a ceremonial visit goes back several years. But because the United States is considered a superpower, its port call takes on considerable symbolic significance. It was also regarded by some officials on both sides as one more sign that U.S.-Chinese relations are moving forward.

But State Department officials said it was not surprising that the Chinese would be particularly sensitive about signals, symbols and appearances as they approach a special Communist Party conference, now set for September. The Chinese have consistently tried in recent years to show that their foreign policy is independent of the United States and the Soviet Union.

On May 9, the official Communist Party organ, the People's Daily, ran a front-page editorial commemorating the 40th anniversary of the victory over the Nazis in Europe that said the superpowers were "still intensifying their rivalry for world hegemony."

A State Department official also said the Chinese might be concerned about the impact on their North Korean allies of having armed U.S. warships enter a Chinese port at a time when the North Koreans seem to be increasing their contacts with the Soviet Union. Chinese troops fought against the Americans in the Korean war.

Another official suggested that a failure of coordination and consultation between the Chinese Defense and Foreign ministries might be involved, much along the lines of some of the U.S. government's interagency differences.

The U.S. and Chinese navies seemed clearly to be in favor of the visit, which had been tentatively set for May 18.

New Zealand has banned U.S. Navy visits unless Washington can provide assurances that the ships are not carrying nuclear weapons. This action created a crisis within the U.S., Australian and New Zealand alliance.

"I think the Chinese got tied up in knots with their . . . statement on nuclear ships," said a senior State Department official at the end of last week. "So it's easier if they back off.

"They probably would prefer to deal with an issue like this without publicity. But they were in the New Zealand spotlight."