Defense Secretary Caspar W. Weinberger and Chinese Premier Zhao Ziyang proclaimed a new warmth in U.S.-Chinese relations tonight, but it remained unclear whether specific new agreements would emerge from Weinberger's current visit here.

Speaking at a rare news conference, Zhao said there has been "a trend for the better in Sino-U.S. relations recently."

Weinberger toasted his Chinese hosts at a banquet on his final night in Peking by saying three days of talks had "set the stage for a greater degree of cooperation than in the past." Weinberger will meet with Communist Party Chairman Deng Xiaoping Wednesday and then will travel to Xian and Shanghai to inspect military installations.

Just before leaving for Xian, Weinberger announced that President Reagan will make his first visit to China next April after Zhao visits the United States in January, The Associated Press reported.

Weinberger also said that his talks with Chinese leaders and defense officials "will mature into, and very quickly, the actual transfers of weapons systems if that's what the Chinese want. We are fully prepared to do that."

Neither side claimed to have achieved anything more than general good feelings, however, and Zhao threw some cool water on several of the U.S. delegation's long-range goals. The top Chinese government official said China has no desire for strategic cooperation with the United States, is unlikely to buy many American weapons and has no plans to exchange military teams for training.

In addition, Zhao complained about U.S. arms sales to Taiwan, a sore point that Pentagon officials had hoped would not be raised during this trip. His rhetoric on the subject was comparatively restrained, however, and officials here took heart that Weinberger's counterpart, Defense Minister Zhang Aiping, never mentioned Taiwan.

Apart from the issue of direct sales of military hardware, Peking and Washington also are discussing sales of high technology items that could have military applications. Prospects for these sales were being thrashed out in talks between lower-level technical commissions and could come up in the meeting between Weinberger and Deng.

Weinberger arrived in Peking Sunday. He is hoping to forge new military ties and accelerate the thaw in relations that began several months ago after two years of discord. Although he tried not to raise expectations that any deals would be cut during his visit, Weinberger came prepared to discuss weapon sales, technology transfers and exchanges of military personnel to compare notes on military medicine, training and logistics.

Zhao held out little hope that the two countries would create significant military ties soon.

"Naturally if the U.S. side is willing to sell military equipment to China and if we have the need and the ability to buy military equipment from the U.S., I would not exclude such a possibility," Zhao said. "But it would be inconceivable for a big nation like China to bring about its modernization of military defense by buying military equipment from foreign countries."

Weinberger is known to believe that China's armed forces, which are huge but 30 years out of date in many areas, should be strengthened to balance a Soviet military buildup in Asia. He emphasized tonight, as he has throughout his visit, the danger he believes the Soviets pose to world peace, but once again he received at best a noncommittal answer from his hosts.

"We do not attach ourselves to any big power or bloc of powers," Zhao said. "Our attitude toward the international issues is, we will determine our position according to the merits of each and every case."

Rather than weapons and military aid, the Chinese have seemed most interested in the easing of export restrictions on sophisticated technology, which the United States announced in principle several months ago. Zhao said the new guidelines would be a symbol of "mutual confidence and trust."

But the premier also made clear that questions remain about the guidelines, which were supposed to have been published days ago but have not been released. U.S. officials are still negotiating with China to ensure that the technology does not end up in third countries such as North Korea.

"Naturally, we would wait to see that these principles will be implemented, will be specified and will be proved by actual deeds and actions," Zhao said.