In an interview with CBS News, Paul said the Pentagon's request for an extra $200 billion is not something he could support. That's despite the fact that troops are continuing to carry out attacks in Iran.
"I won't vote for the supplemental because I don't want the war to continue," the senator said. "Most people will accept the argument and say you can't quit funding them, they're over there, they're in the battle... But actually if they weren't funded, they'd be brought home."
Paul has long cited President Donald Trump's "instincts" against foreign wars as a key point of agreement between the two, but the now month-old war in Iran is testing that proposition. Asked about the fallout, Paul said he believes a decision by the president to stay in Iran could damage his own party's prospects at the ballot box in November.
"The economic costs are very clear and in the political landscape, I think the longer this goes on the less likely Republicans are able to hold on to the House and the Senate," the Bowling Green lawmaker added.
The White House continues to send mixed messages on Iran, with Trump saying the country's leaders are asking for a ceasefire — a claim the Iranian regime denies.
Trump is scheduled to address the nation tonight at 9 p.m.