SOUTH KOREA TO MAINTAIN TRADE SURPLUS 3-5 YEARS South Korean Trade Minister Rha Woong Bae said his nation would maintain a trading surplus for three to five years as a way to cut its foreign debt. He said in an interview with Reuters that after a few years it was likely South Korea would drop barriers to foreign goods and move toward a more balanced trade position. He said the present trade surplus was vital if his nation was to reduce its 44.5 billion dlr foreign debt. Rha said that 1986 was the first year South Korea had a trade surplus - 4.5 billion dlrs, against a 1985 deficit of 900 mln dlrs. Asked if South Korea would drop its trade barriers once its foreign debt was substantially reduced, he said "yes, I think so." Rha made his remarks at the end of a two-week trade mission here during which a team he led agreed to buy U.S. products valued at 1.8 billion dlrs. About 800 mln dlrs of the purchases are in goods of the type South Korea normally bought from Japan. Rha was to leave later today for Ottawa for trade talks with Canadian officials and businessmen. He said in the interview the U.S. purchases were to reduce his country's 7.1 billion dlr surplus with the United States and also to cut its 5.6 billion dlr shortfall with Japan. Rha said it was also due to a shift in exchange rates between the U.S. dollar and the yen that made it cheaper to buy U.S. goods than Japanese goods. He said South Korea heavily relied on foreign trade and he hoped the leaders of major trading nations could find a way to resolve the growing trend toward protectionist legislation. Rha said "I hope the leaders can get together to find a solution by making some mutually satisfactory concessions." But he added "the leaders seem hesitant to make concessions because of domestic political reasons." Speaking of his own country, he said "We have made a lot of concessions already." He cited regulations permitting foreign investment in industrial firms, allowing increased foreign banking activity and cracking down on piracy of intellectual property by strengthening protection of copyrights and patents. Rha said South Korea had also lowered many of its tariffs. Asked if South Korea would retaliate against U.S. goods if Congress closed U.S. markets to its products, he said "at this moment, we have no thought of retaliation." South Korea is a major exporter to the United States of textiles and apparel and electronic goods, such as television sets, video cassette records and personal computers. Its puchases from the United States include electronic testing equipment and grains and cotton. The trade mission's purchases here included three Boeing passenger planes for 400 mln dlrs, four McDonnell Douglas planes for 300 mln dlrs; and machinery worth 725 mln dlrs.