Copter Pilot Still in North Korean Hands; U.S. Seeks High-Level Talks : Asia: Administration earlier expressed regret for violating airspace. Washington to reassess situation today.

Christmas Day came and went in North Korea with Chief Warrant Officer Bobby Hall still in captivity and the Clinton Administration seeking a high-level meeting today with North Korean military officers before deciding whether to increase American pressure to gain the downed aviator’s freedom.

With few attractive alternatives available to it eight days after Hall’s helicopter was shot down three miles into North Korean territory, the Administration deliberately took a low-key approach Sunday as it sought a response from Pyongyang to a letter delivered over the weekend to North Korean officials.

In the letter, the United States expressed regret for the incident and attributed the intrusion to a navigation error.

But, a senior Administration official suggested, the passage of the holiday with no movement by the North Koreans would put more pressure on Washington to up the ante.

Secretary of Defense William J. Perry and Gen. John M. Shalikashvili, chairman of the Joint Chiefs of Staff, conferred Saturday evening, but no meetings were held in Washington on Sunday, the senior official said.

He added that, if there is no sign of progress by this morning--the end of the business day in Korea--the Administration will probably reassess the situation.

“On Monday, we’ll have to decide,” he said, while adding that no meetings were scheduled and no specific steps had been set.

Officials in Washington expressed guarded hopes that the North Korean military would dispatch a ranking officer to meet with a senior U.S. military officer in Panmunjom, the truce village between North and South Korea, and present an official response to the apologetic letter, written by Gen. Gary E. Luck, supreme commander of the 37,000 U.S. troops in the South.

As of Sunday afternoon, officials in Washington had no word from U.S. officials in Seoul on whether such a meeting would take place.

The United States had made clear that it wanted Hall released by Christmas, and the North Koreans now may feel free to release the downed flier without appearing to give in to an informal but symbolically important American deadline.

U.S. officials had hoped that the three-paragraph letter, delivered during a low-level military meeting Sunday in Panmunjom, would break the stalemate.

Hall and his co-pilot, David Hilemon, were shot down Dec. 17 when their OH-58 reconnaissance helicopter, which U.S. officials say was unarmed, strayed across the demilitarized zone.

U.S. officials have said that heavy snow, which obscured navigational signs and other landmarks on the ground, may have disoriented the pilots.

The United States has said the helicopter was on a training mission; North Korea has said it was on a spying mission.

Hilemon’s body was turned over to American officials Thursday. Nothing has been heard from Hall, believed to be at a North Korean military base. But North Korean officials have said he is in good health.

Hall is from Brooksville, Fla., where local residents have decorated trees with yellow ribbons to call for his safe and speedy return.