The United States added North Korea to its list of countries practicing international terrorism and withdrew a recent gesture of conciliation yesterday to protest "compelling evidence" that Pyongyang was responsible for the bombing of a South Korean airliner in which 115 people died.

State Department spokesman Charles E. Redman, who announced the moves, said North Korean actions "just don't live up to the standards of civilized behavior."

Redman said the United States is calling on countries with close ties to North Korea to condemn its complicity in the airliner bombing Nov. 29 and said U.S. diplomats would back South Korean efforts to penalize North Korea in international forums.

The U.S. actions, largely symbolic, grew out of the midair explosion that destroyed a Korean Air jet off Burma during a flight from Baghdad to Seoul.

A 26-year-old woman, who had been on an earlier leg of the flight and was taken into custody by South Korean authorities, announced last Friday in Seoul that she had planted a time bomb on the plane under orders from Kim Jong Il, son of North Korean leader Kim Il Sung.

The woman, who identified herself as Kim Hyon Hui, said that her father is a North Korean diplomat and that she was trained in North Korea as an agent for undertaking terrorist and intelligence missions.

State Department sources said U.S. officials interviewed the woman, carefully investigated her story and obtained "independent confirmation" of it before taking the actions announced yesterday.

U.S. authorities do not expect South Korean military retaliation against the North, especially after a statement from Prime Minister Kim Chung Yul ruling out such action, a State Department official said.

Large-scale rallies to protest the bombing are expected in Seoul, however, and the South Koreans are anxious to win international backing for their condemnation of the terrorist act, according to the U.S. source.

Blaming North Korea for the bombing would seem to end any chance that the Pyongyang regime will participate in the Olympic Games scheduled for October in Seoul.

The head of the Seoul Olympics committee said North Korea would be allowed to participate if it apologizes for the bombing and punishes those responsible, but this is considered unlikely.

The United States has no diplomatic relations or trade with North Korea, and contacts have been minimal since the 1950-53 Korean war.

Last March, in a conciliatory gesture, North Korea was informed that U.S. diplomats would be willing to hold substantive conversations with Pyongyang's diplomats at receptions and other "neutral" locations.

U.S. permission for these contacts, which officials said produced several desultory conversations but no movement toward agreements, has been cancelled because of the bombing.