The US Embassy in Kyrgyzstan said Wednesday that talks will continue on maintaining a key American air base in the country despite the Kyrgyz president's announcement that it will close. The base in the former Soviet Central Asian country is an essential element of support for US and international operations in Afghanistan. Kyrgyzstan's president announced Tuesday that the country had decided the Manas base must close. He did not specify when the closure might take place. But a US Embassy statement Wednesday said the United States has received no formal notification of the decision. "We have been in discussions with Kyrgyz authorities on the future of Manas air base. These discussions will continue," the statement said. The announcement by Kyrgyz President Kurmanbek Bakiyev posed a serious challenge to the new U.S. administration and President Barack Obama's plan to send up to 30,000 more American forces into Afghanistan this year. Some 75 percent of US supplies to Afghanistan currently travel through Pakistan, but increasing attacks on transport depots and truck convoys there have raised doubts about Pakistan's ability to protect the vital route - and increased the necessity for alternative routes through Central Asia. The main supply route through Pakistan was severed Tuesday when suspected militants set off a bomb that wrecked a bridge across a rocky gorge near the pass. On Wednesday, assailants torched 10 stranded trucks. The Kyrgyz base, at the Manas airport near the capital, is an important air-mobility facility, home to tanker planes that refuel warplanes flying over Afghanistan. It also supports airlifts and medical evacuation operations and houses troops heading into and out of Afghanistan. But Kyrgyz officials complained that the United States was underpaying the impoverished country for the base and public resentment spiked in 2006 when an American serviceman fatally shot a Kyrgyz truck driver during a security check at the base entrance. Russia, although nominally supportive of the anti-terrorism campaign in Afghanistan, resented the US military presence in a country it regards as part of its traditional sphere of influence. Russia established an air base in Kyrgyzstan about two years after the U.S. base went into operation. Bakiyev's announcement in Moscow of the base closure came shortly after the announcement of $2.15 billion in Russian loans, investments and other aid to Kyrgyzstan.