(Yonhap) -- South Korea faced a nerve-wracking several months in 1977 after the administration of then-U.S. president Jimmy Carter held up arms sales to foreign countries worth about US$6 billion, Seoul's declassified diplomatic documents showed Sunday.

   The documents revealed that South Korean officials were worried about the months-long arms sales moratorium by Carter, who had at that time contemplated withdrawing ground combat troops from South Korea.

   Carter's sudden decision to withdraw U.S. troops from South Korea -- an idea later abandoned in 1978 -- further hurt Seoul's confidence in Washington during the military presidency of Park Chung-hee.

   Unlike his predecessor presidents Nixon and Ford who encouraged arms sales to strengthen the U.S. trade balance after the price of oil quadrupled in 1974, Carter hoped to change his country's arms sales policy.

   On Jan. 19, 1977, the U.S. Department of Defense notified Congress of its pending arms sales to foreign nations, including South Korea, but no approval had been made since Carter took office a month earlier.

   South Korea's foreign ministry ordered its diplomats in Washington to report back with the reason why the Carter administration put an "undeclared moratorium" into effect, according to the documents.

   Such disclosures were revealed Sunday as part of the foreign ministry's annual release of diplomatic documents.

   On March 29, 1977, the Carter administration approved sections of arms sales to South Korea, but Seoul officials became frustrated again in May because the U.S. did not explicitly categorize South

Korea as a country which was excluded from Washington's new arms sales controls policy.

   Yoon Ha-jeong, Seoul's then-vice foreign minister, called in Thomas Stern, the U.S. deputy chief of mission in Seoul, and said that Washington should grant an exemption for South Korea.

   "Korea was not explicitly included in the list of exempted countries," Yoon told Stern, according to the documents. 

"In line with a mutual defense treaty and the U.S. plan to strengthen Korean troops, Korea should be excluded from the U.S. policy of arms sales controls." 

Stern assured South Korea that it would get an exemption.

   On July 13, the U.S. notified South Korea that it approved an arms deal with Seoul worth about US$300 million.

   In October, John Kelley, first secretary of the U.S. embassy in Seoul, also wrote a letter to the foreign ministry, saying "Congress was provided formal certification on September 15 regarding the proposed FMS sale of Sparrow Missiles, including support, to the Republic of Korea (South Korea)."