WASHINGTON - THE White House said on Thursday it would work with the government of Kyrgyzstan to 'remedy' its decision to close a US air base which has been 'vital' in the war in Afghanistan.

The decision by the Central Asian state could prove a problem for the administration of President Barack Obama as the base was likely set to play a key role in his plans to boost US troop numbers in the Afghan war.

'We've seen the reports and I believe we've been in consultation with leaders there,' White House spokesman Robert Gibbs told reporters.

'Obviously, Kyrgyzstan has provided an important air base in Manas that has been vital to our efforts and coalition efforts in Afghanistan and we look forward to working with them to remedy that situation,' Mr Gibbs said, referring to the closure plans.

Kyrgyz President Kurmanbek Bakiyev first announced the closure of the base in Moscow, fueling speculation the decision came under pressure from Russia, which has been irritated by the US presence in ex-Soviet territory.

Earlier, Secretary of State Hillary Clinton said the decision was 'regrettable' but said US operations in the region would continue to be effective, no matter what happened.

'With respect to the base, the defense department is conducting an examination into how else we would proceed,' Mrs Clinton told reporters after talks with French Foreign Minister Bernard Kouchner.

'It will not affect whatever decisions we make. It is regrettable. This is under consideration by the government of Kyrgyzstan and we hope to have further discussions with them.

'But we will proceed in a very effective manner no matter what the outcome of the Kyrgyzstan government's deliberations might be.' The closure of the Kyrgyzstan air base would strain US supply lines at a time when Mr Obama is preparing to nearly double the 36,000-strong force in the country and amid increasing attacks on supply routes through Pakistan.

About 15,000 people and 500 tonnes of cargo move in and out of the Manas air base every month supporting the Nato force in Afghanistan as well as the Afghan army, the US Defence Department said on Wednesday.

The base remains the only US outpost in Central Asia after the US military was evicted from Uzbekistan in 2005 following Washington's condemnation of Tashkent over human rights violations.

US officers in charge of transportation were already exploring other routes to supply the 36,000 troops deployed in Afghanistan after repeated attacks on a key road in Pakistan used to ferry supplies through the Khyber Pass to Afghanistan.

The Manas base, operated by about 1,000 troops including small French and Spanish contingents, was set up to support coalition forces fighting to oust the Taleban regime in Afghanistan in the wake of the Sept 11, 2001 attacks. -- AFP