The underlying bill, H.J.Res. 66, was originally designed to renew import sanctions on the ruling military junta in Burma, but Senate Democrats are hoping to turn it into an appropriation for FEMA.

In a deal struck Thursday afternoon, Democratic leadership permitted debate and votes on the two amendments in exchange for Coburn lifting his filibuster on the bill, which he had threatened to sustain through the weekend.

Had it continued, the filibuster would had jeopardized the Senate's ability to act on a Federal Aviation Administration (FAA) and highway funding bill approved on Tuesday by the House. Taxes funding the FAA expire Friday, leading many senators to accuse Coburn of risking more than 80,000 jobs with his hold on the FEMA bill.

Preceding the second amendment vote, which would defund 10 percent of USAID, Paul remarked that foreign aid is "opposed by 77 percent of Americans" and that any money given away would be borrowed anyway.

"Even if you thought it was a good idea to give welfare to foreign countries, you don't have it," he said to his colleagues.

In a rebuttal, Senate Foreign Relations Committee Chairman John KerryJohn KerryTrump fails to mention Clinton in inaugural address Hillary Clinton under microscope at inauguration Overnight Tech: Meet the key players for Trump on tech | Patent chief staying on | Kerry aide goes to Snapchat | Uber's M settlement MORE (D-Mass.) rejected Paul's argument that foreign aid is like welfare.

"Foreign aid is an investment in our national security. It is not a gift to other countries," he said.

"This amendment would be absolutely devastating to our foreign aid and development programs. It would decimate agencies that have already taken huge funding cuts in fiscal year '11, and would completely undermine core national security priorities and humanitarian commitments."