Krakow, Poland - US Defence Secretary Robert Gates said Friday he remained hopeful that a "reasonable" deal could yet be reached with Kyrgyz officials preventing the closure of the United States' only air base in Central Asia, which supplies US and NATO operations in Afghanistan.

"I continue to believe that this is not a closed issue and there remains the potential at least to reopen this issue with the Kyrgyzs and reach a new agreement," Gates said at a meeting of NATO defence ministers in Krakow, Poland.

Krakow, Poland - German Defence Minister Franz Josef Jung said Thursday he opposed US plans to use NATO's embryonic Response Force (NRF) to provide security in Afghanistan during the country's presidential elections.

"The NRF should not be considered as a reserve force. In principle, it has a very different role to play," Jung told reporters ahead of a meeting of NATO defence ministers in Krakow, Poland.

Other European allies are understood to also oppose the deployment of the NRF in Afghanistan.