The United States is discussing the possibility of using Turkmenistan''s airspace to support the battle in neighbouring Afghanistan, a top US State Department official said Thursday.

US Assistant Secretary of State Richard Boucher said that he discussed the possibility of using the Central Asian state''s airspace with Turkmen President Gurbanguly Berdymukhamedov and was hopeful an agreement could be reached.

"We talked about permitting American aircraft to fly via their territory and transport various supplies. We have raised this question with every country in the region. We are hopeful of cooperation in this area with Turkmenistan," he told reporters through a translator.

Berdymukhamedov first raised the possibility of opening up his isolated country''s airspace to the transport of non-military cargo at a press conference in neighbouring Uzbekistan in February.

The United States has been actively searching for alternative supply routes into war-wracked Afghanistan since Kyrgyzstan announced earlier this year that it would be expelling coalition forces from a key airbase on its territory.

The announcement of negotiations comes at a time of increasing tensions between Turkmenistan and Moscow over a gas pipeline explosion last week, and as Ashgabat appears to be opening up to greater cooperation with the West.