Kazakhstan has said it will allow the United States to ship non-military cargo via its territory to Afghanistan.
The foreign ministry said it had given its consent to the transportation of "material for civilian use" by land.
Kazakhstan does not border Afghanistan, but shares frontiers with three other Central Asian countries which do.
The move comes after Kyrgyzstan said it would close the only US base in Central Asia at Manas, which the Pentagon has described as hugely important.
The Kyrgyz government asked parliament to give the US six months' notice to leave the Manas base, after Russia promised Kyrgyzstan $2bn (£1.4bn) in aid. A parliamentary vote is expected this week.