TOKYO -- In what it termed a cautionary step, South Korea placed its troops on alert yesterday, but officials said they saw no sign of troop movements or unusual activity in North Korea a day after that country's Communist government said it would pull out of the Nuclear Nonproliferation Treaty.
The alert came as South Korea's military exercises with the United States, known as Team Spirit, continued well south of the heavily armed Demilitarized Zone.
North Korea has called the exercises a rehearsal for staging an invasion, and cited them as one of the reasons that it became the first nation ever to renounce the treaty. The United States says that the annual exercises, which began in 1976, are purely defensive.
Leaders of the South Korean government of President Kim Young Sam, who took office two weeks ago, spent most of the day deciding how to respond to North Korea's surprise action. But so far Seoul has said little, other than to say that the action "heightens the suspicion" that North Korea is developing nuclear arms.
Along with the United States and Japan, South Korea has called on North Korea to retract its decision before it becomes effective in 90 days.
"There are a lot of discussions about what to do next, but the border is very quiet," Ryu Myung Hwan, the spokesman for the South Korean Foreign Ministry, said yesterday afternoon.
Secretary of State Warren M. Christopher said Friday that he believed North Korea's withdrawal from the treaty and its refusal to allow inspection of two suspected nuclear sites would likely be taken up by the United Nations Security Council unless the hard-line government of President Kim Il Sung reversed its course.
NB In Pyongyang, the North Korean capital, officials repeated yes
terday their warnings to the United States and other nations not to press for economic sanctions or other pressure in response to North Korea's decision, according to reports on the official state news service monitored in Tokyo.
"We are fully prepared to take appropriate countermeasures," Kang Sok Jue, North Korea's vice minister for foreign affairs, was quoted as saying in Pyongyang. He said that the military could "face any offensive and pressure by the enemies."
So far, North Korea has said nothing to suggest that it is preparing any kind of offensive military movement. But earlier in the week, in response to the beginning of Team Spirit, the country said it was going on a "semi-war footing" to guard against any attack launched during the exercises.
Military alerts for South Korea's 650,000 troops are relatively common. A low-level alert is routine during Team Spirit exercises. Higher-level alerts, like the one issued yesterday, have been declared after border incidents and during special events, like the 1988 Summer Olympics in Seoul.