"This is part of a number of consultations that Ambassador Holbrooke has had with countries that are helping us in Afghanistan, have a number of cooperative programmes with Afghanistan and Pakistan," State Department spokesman Ian Kelly said.

"He has been wanting to go there, I know, for several months, so this is something that's been planned for some time, and it's part of his ongoing consultations with a number of countries that are involved in the effort in Afghanistan," Kelly said.

In addition to Holbrooke's meetings with senior officials, there are also US technical teams in Moscow right now who are discussing with Russian counterparts assistance coordination and also implementing modalities of the transit agreement that the US recently concluded with Russia. These talks will continue for another day.

The US-Russia Air Transit Agreement provided the Government of Russia with a review and comment period which has just concluded, Kelly said.

"This is one of the reasons for the technical team going now and not earlier. One of the points that we are trying to iron out is notification processes that have to be in place," Kelly said.

"We are also working with other countries on the transit routes since anything over-flying Russia to go to Afghanistan would have to fly over other countries as well," he said.

The agreement was announced by the two presidents when they met in July.