Tajikistan has agreed to offer its airspace for transport of non-military NATO supplies to Afghanistan to help Washington boost its transit lines in the region, the US ambassador to Tajikistan said on Friday.

The move comes after Kyrgyzstan said it would shut down a key US military airbase on its territory, leaving the United States scrambling to find alternative supply routes for NATO forces in Afghanistan.

"The (Tajik) president confirmed his readiness to offer the country's airspace for non-military NATO supplies bound for Afghanistan," Ambassador Tracey Ann Jacobson, speaking in Russian, told reporters.