The Reagan administration has agreed to sell South Korea sophisticated F16 warplanes and expects to submit the proposed sale for congressional approval soon, U.S. sources said yesterday.

The new administration's agreement to supply the aircraft, which have long been at the top of the Seoul's wish list, was conveyed to the official party of visiting South Korean President Chun Doo Hwan, according to the Sources. This was made known as Chun left Washington for Hawaii, after addressing the National Press Club, on the last leg of his 11-day U.S. tour.

The go-ahead for the aircraft sale, together with the prospect of a modest increase in credits for arms purchases, appears to be the substance behind President Reagan's statement Monday, in a joint communique with Chun, that the United States will make available for sale "appropriate weapons systems and defense industry technology for enhancing Korea's capabilities to deter aggression."

The Carter administration as early as mid-1977 agreed "in principle" to supply the advance U.S. warplane to the South Korans at an unspecified time. However, economic and political problems, including those connected with the Carter plan to withdraw U.S. ground troops from Korea, prevented the deal from going through.

Korea, in the meantime, has shaved its request from 60 to 36 F16s, partly because of their high cost. Seoul has not said officially that it wants to make the purchase, but meetings with high Korean officials here this week suggested to U.S. officials that it is likely to soon.

One reason for hesitance among some Washington officials in the past was concern that introduction of high-performance aircraft into the South Korean inventory might force the Soviet Union to provide sophisticated aircraft to its North Korean ally. North Korea's most advanced combat plane is the Mig21, which was supplied by the Russians in the mid-1960s.The Soviet Union has conspicuously failed to supply Pyongyang with the Mig23 and other more-advanced warplanes that have been made available to other Soviet allies.

U.S. officials said this argument has been rejected on several grounds. Among them, the sources said, is that fact that later this year the U.S. Air Force will begin assigning the F16 to its forces in South Korea, in place of the F4, the combat standard until now.

In his address to the National Press Club , Chun did not mention the U.S. offer to sell the warplanes. But he said that while he is "gratified" by Reagan's assurance U.S. troops will not be withdrawn from South Korea, "let me assure you that we will continue to do our share and assume the major burden of defending our country."

In answer to a question, the Korean president said the 39,000-strong U.S. military force in his country "serves U.S. strategic interest, stays the hand of Soviet expansionism and serves the interest of stability among the four powers [the United States, Japan, China and the Soviet Union] which have an interest in the area." Chun also said presence of U.S. forces in South Korea helps keep the Soviets "tied down" in Northeast Asia.

The former general also stressed, in addition to military aspects, Korea's economic needs, calling economic growth an "urgent" task for his country and blaming its unusual economic decline last year on internal political instablity.

On the political side, Chun bluntly criticized his former sponsor, assassinated president Park Chung Hee, saying that "political strife in Korea in the 1970s resulted mainly because one person held the reins of power too long." Chun promised to work toward strengthening constitutional order, including "above all, the guarantee of a peaceful transfer of political power." Chun is expected to be elected later this month, by indirect means, to a seven-year term as president.