The government of Taiwan has indicated it wants to buy high-performance F16 jet fighters from this country, a proposal that confronts the Reagan administration with the delicate problem of balancing its foreign policy toward Asia between old friend Taiwan and new friend China.

Though no decision has been made, informed sources say that a number of senior administration officials, including some in the White House and Pentagon, are in favor of selling the jets and that there is strong feeling among them that "it is important for the U.S. to maintain the friendship of Taiwan."

In the State Department, however, there is said to be a more cautious attitude toward any sale, because it could anger mainland China and perhaps cost the United States some influence there when Washington is looking for all the company it can find to bring pressure against the Soviet Union.

The Taiwan air force, with roughly 400 planes, has always been equipped with U.S.-built aircraft, and the indications that Taiwan is ready for a more modern and capable plane to replace its F5 fighters comes as no suprise.

The potential problem with China, however, comes from the expected formal request from Taiwan for the F16. The F16 is among the best and newest U.S. fighters and -- even though the mainland Chinese have a vastly larger air force -- conceivably could be trouble for Peking if the two Chinese republics ever clashed.

Congressional sources say the fighter decision is a key undecided question in an interagency review going on in the new administration and aimed at ironing out the new policy toward mainland China.

The issue is not only delicate in foreign policy terms for Washington, it may also be a sensitive question between President Reagan and the State Department, which is run by one of Reagan's key Cabinet officers, Alexander M. Haig Jr.

Some officials close to Haig believe that, though Reagan wants good relations with Peking, he has "a little bit of a blind spot when it comes to Taiwan," meaning that the president's longtime feeling of closeness and friendship toward Taiwan may make it difficult to manage relations skillfully with Peking.

In December 1978, the Carter administration reduced "official" U.S. ties to Taiwan as part of an agreement with Peking that established "normal" diplomatic relations with the People's Republic of China. At the time, Reagan denounced Carter's move as "an outright betrayal of Taiwan," and several times during the subsequent election campaign candidate Reagan said he would advocate reestablishment of official relations with Taiwan.

It is not yet clear what model of the F16 Taiwan will get if a decision is made to supply the planes. The version already in the hands of the U.S. Air Force has a very high-powered engine that gives the plane long range and high speed. But the plane's manufacturer. General Dynamics Corp., also has developed an "export version" with a less powerful engine that presumably may look less threatening as viewed from the Chinese mainland.

Another possibility is an advanced version of the Northrop F5. But several sources said they thought it was clear that Taiwan, perhaps for prestige and defense reasons, wanted the hotter and faster F16.