Patriot Missiles Arrive in S. Korea : Defense: First shipment is unloaded as U.S. steps up pressure on North Korea to allow inspection of its nuclear sites.

The first shiploads of U.S. Patriot air defense missiles arrived in Seoul on Monday as the United States prepared to step up pressure on North Korea to allow international inspection of its nuclear facilities.

American officials said the shipment of three batteries--containing half the 48 missile launchers that President Clinton has ordered deployed to South Korea--were unloaded at Pusan; more are expected later this week.

The action came as Robert Gallucci, Clinton’s newly appointed policy coordinator for Korean issues, warned in a visit to Seoul that North Korea will face international economic sanctions if it does not comply soon with requests to allow the inspections. North Korea has denied charges by Western officials that it is trying to develop nuclear weapons.

Meanwhile, Defense Secretary William J. Perry left for Seoul on Monday afternoon for high-level talks with South Korean leaders and U.S. military commanders there.

American officials said that unless North Korea relents soon, Perry probably will announce the resumption of the annual U.S.-South Korean “Team Spirit” military exercises. The exercises had been postponed pending resolution of the nuclear dispute.

Although the maneuvers are not essential to U.S.-South Korean military readiness, they are important symbolically because North Korea has made so much of them politically, conducting its own exercises to counter them.

In what U.S. officials regard as mere rhetoric, Pyongyang has warned repeatedly that it would regard resumption of the U.S.-South Korean exercises as “an act of war.” Washington has decided privately to renew them anyway.

Perry’s visit is designed partly to underscore American and South Korean resolve on pressuring North Korea to comply with demands that it submit to international inspections of its nuclear facilities.

Washington already has begun deploying Apache attack helicopters to American forces in South Korea, replacing Army Cobras. And although the Pentagon denies it, private analysts say the Navy has sent more ships to the area.

The Pentagon has announced plans to bolster the stockpile of parts and equipment for American and South Korean jet fighters that would be used to provide tactical air support in case of a military conflict.

Perry has said repeatedly that he sees no imminent danger of a North Korean attack, and officials say American and South Korean troops are not officially on alert.

But North Korea has about 1.1 million troops massed near the South Korean border and has assembled large numbers of tanks and artillery batteries ready to move across the line in any attack.

Despite the timing of the delivery of the Patriots, American officials continued to stress that the deployment is strictly a defensive move and does not signal a more aggressive allied military posture in the area.

The Patriot batteries are to be set up around airports and major cities to help fend off possible attacks by North Korean Scud missiles, should Pyongyang decide to wage war.

The diplomatic situation in the dispute over inspections of nuclear facilities has been stalled for almost a month, with Washington waiting for the North Koreans to respond to the latest U.N. demands that they comply.

The U.N. Security Council took up the issue last month but--at China’s insistence--postponed any action on imposition of sanctions in order to give Pyongyang another chance to drop its refusal to allow inspections.