Until now, most supplies destined for the 140,000-strong international force in Afghanistan were shipped to the Pakistani port of Karachi, and then trucked to the landlocked nation. But with the Taliban and their sympathizers targeting the convoys, military planners sought other alternatives.

The development is important because it signals Russian willingness to indirectly support the NATO-led mission. Moscow has been warmer to the mission's success in recent years, fearing that a NATO defeat in Afghanistan could destabilize central Asia and endanger Russia's security.

Although Russia offered to open its territory to NATO as a whole two years ago, the alliance did not immediately take them up on the offer. After a spate of ambushes in Pakistan in 2009, NATO started negotiating transit rights with Uzbekistan and Kazakhstan, which took almost a year to complete.

Individual alliance members, such as Germany and the United States, were allowed to use the so-called northern route for non-lethal materials — but it was closed to alliance forces as a whole. About 14,000 maritime containers full of supplies had arrived via the northern route before it was opened to the whole alliance, U.S. Defence Secretary Robert Gates said.

"The central Asian states and Russia are playing a key role both in terms of ground transportation and overflights."

There are two other possible access routes to Afghanistan, through Iran and China. But the alliance cannot use the one through Iran's southeastern port of Chahar Bahar because of the political dispute over Tehran's nuclear weapons. Meanwhile, a dirt road from China through the Wakhan Corridor, leads through some of the world's most mountainous terrain and is blocked by snow for much of the year.