Kentucky Republican Senator Rand Paul defied leaders of both parties and unilaterally delayed until next week the Senate's approval of an additional $40 billion in military aid to Ukraine.

Although the Senate was ready to debate and vote in favor of the military and economic aid package, Paul prevented leaders from securing the unanimous support that was needed to get the bill through quickly.

The bill had previously been overwhelmingly approved in the House and had strong support from both parties in the Senate. That the document will eventually pass is not in doubt, the Voice of America reports.

It was Rand Paul's rebellion against his fellow Kentucky Republican and Senate Minority Leader Mitch McConnell. McConnell began Thursday’s session by saying senators from “both sides” — meaning Republicans and Democrats — needed to “help us pass this urgent funding bill today,” gesturing emphatically as he said “today.”

Paul, a libertarian who often opposes U.S. intervention abroad, said he wanted language inserted into the bill, without a vote, that would have an inspector general scrutinize the new spending.

Rand Paul argued that the additional spending exceeds U.S. spending on many domestic programs, is comparable to Russia's entire defense budget and would exacerbate federal deficits and inflation.

“No matter how sympathetic the cause, my oath of office is to the national security of the United States of America,” Paul said. “We cannot save Ukraine by dooming the U.S. economy.