Washington put a $53 million arms agreement with Bahrain on hold to wait out a report from an independent commission monitoring the human rights situation in Bahrain.
Amnesty International, in an assessment of arms transfers, criticized nations like the United States, Russia and several European countries for supplying weapons to regimes that later responded with force to anti-government protesters.
Mark Toner, a spokesman for the U.S. State Department, said Washington supports Bahrain's right to self-defense.
"Whenever we conduct these kinds of sales, whether they be to Bahrain or elsewhere in the world, we always include an end-use monitoring component that allows us to see if these are being used for the purpose for which they were intended," he added.
Bahrain called in security support from members of the Gulf Cooperation Council for help in responding to a Shiite uprising against the Sunni regime early this year.
Toner added that it could be "a matter of months" before vetting procedures regarding arms sales are completed.
The Pentagon in September notified Congress of the proposed sale of armored vehicles and wire-guided missiles to Bahrain.