American officials were optimistic Monday about the release of American pilot Bobby Hall, held captive by North Korea for more than a week, despite a high-level meeting that yielded "no substantive progress."

U.N. officials discussed Hall's release with North Korean army generals at the truce village of Panmunjom in the Demilitarized Zone that separates the two Koreas."No substantive progress was made, and the KPA would not set a date for Hall's release, maintaining that their investigation into the incident was still continuing," the United Nations Combined Forces Command said in a statement.

But Jim Coles, spokesman for U.S. and U.N. forces in South Korea, said "The meeting itself is a positive sign."

The officers agreed to meet again "in the near future." Coles said officials hoped to meet Tuesday.

Hall has been held since his U.S. Army helicopter strayed into North Korea on Dec. 17 and either was shot down or crashed. His co-pilot, Chief Warrant Officer David Hilemon, was killed. Hilemon's body was returned last Thursday.

The command said U.N. officials "continued to press for Hall's immediate return and stressed that the border crossing was inadvertent and a routine training flight."

The officers agreed to meet again "in the near future." Coles said it was possible another session could be held Monday.

U.S. Rep. Bill Richardson, who helped worked out the repatriation of Hilemon's body, had said North Korea had agreed to free Hall "very soon." He had hoped that meant by Christmas.

Pyongyang has said Hall is in good health but has allowed no foreign contact with him.

The pilots said in their last radio contact that they were still in South Korea, when in fact they were 31/2 miles north of the border. U.S. officials have speculated that the pilots became disoriented because of heavy snow that covered landmarks and navigational placards.