Russia''s General Staff said Thursday it was concerned by the nature of cargoes the United States was airlifting to Georgia, questioning if they were really humanitarian aid.

The U.S. sent two C-17 military planes to Georgia late Wednesday and early Thursday as part of a Pentagon humanitarian mission.

In a statement Wednesday, President George W. Bush said Washington would "use U.S. aircraft, as well as naval forces" to distribute supplies, and demanded Russia withdraw troops from Georgia.

At a news conference Thursday, Col. Gen. Anatoly Nogovitsyn, deputy head of the General Staff, urged the media to press U.S. officials for trustworthy information on the U.S. role in Georgia.

"What is going on there?" he asked. "We, the Russians, are extremely concerned about it."

"U.S. military transport aircraft are reported to have been airlifting some humanitarian cargoes to Tbilisi airport. Two days ago, reports said we had destroyed the airport," Nogovitsyn said

Nogovitsyn denied reports by Georgian officials and Western media that Russian troops had blown up Georgia''s Black Sea port of Poti.

"This is not true. We have not been engaged in any military action for two days, only conducting reconnaissance," he said.