U.S. officials say Uzbekistan has given the United States formal notice that it must leave an airbase that is a key link for military and humanitarian supplies sent into Afghanistan.
State Department spokeswoman Nancy Beck said Saturday Uzbekistan delivered a notice to the U.S. embassy in Tashkent late last week informing officials of the termination of the agreement to use the Karshi-Khanabad airbase.
The Central Asian nation asked the United States to remove all of its aircraft, personnel and equipment from the base within six months.
Uzbekistan did not give a reason for the move, but Ms. Beck said this was a bilateral agreement that could be terminated at any time by either nation.
Relations between Tashkent and Washington have been tense since May, when President Islam Karimov's government killed hundreds of people while suppressing protest demonstrations in Andijan province, near the border with Kyrgyzstan.