The five are wanted in Uzbekistan on charges connected with a violent clash between demonstrators and security forces in the town of Andijon in May 2005.
In a statement, commission chairmen U.S. Senator Sam Brownback (Republican, Kansas) and U.S. Representative Christopher Smith (Republican, New Jersey) say they are "outraged" by the Kyrgyz move to extradite the five Uzbek nationals.
Brownback says the international reputation of Kyrgyzstan -- which had earlier allowed the UN to resettle Uzbek refugees to third countries -- will "certainly" suffer from its "change of policy."
Kyrgyzstan announced its decision on August 9.
All five deportees had sought shelter in Kyrgyzstan following the bloody military crackdown in Andijon. They were arrested shortly after and jailed in the southern city of Osh.
The OSCE chairman in office, the EU's Finnish presidency, and the UN's refugee agency have all condemned Kyrgyzstan's decision.