WASHINGTON, October 8 (RIA Novosti) - U.S. President Barack Obama has received a formal request by a U.S. top military commander to send additional troops to Afghanistan, a White House spokesman has said.

Robert Gibbs said the issue could be discussed this week.

"It [the discussion] could happen as early as Friday, it could be next week," he told a media briefing.

General Stanley McChrystal, the Commander of NATO's International Security Assistance Force (ISAF) has asked President Barack Obama to authorize sending up to 40,000 additional troops to Afghanistan to fight effectively the Taliban militants.

Obama has already ordered the deployment of 17,000 additional U.S. military personnel to the war-ravaged country, but has said that he is not ready to make a final decision on further increases until he had a clear vision of the right strategy for U.S. forces in Afghanistan.

Earlier on Thursday U.S. State Department spokesman Philip Crowley said the U.S. is making preparations for military transit to Afghanistan via the Russian territory, dismissing earlier media reports that Russian-U.S. cooperation on the issue has been halted for a number of financial reasons.

Moscow and Washington signed deal on military transit to Afghanistan, both overland and by air, on July 6, during President Barack Obama's visit to Russia.