Sen. Rand Paul (R-Ky.)  urged President Obama late Thursday against getting involved militarily in Syria, suggesting that it would be a "big mistake."

"There are potential repercussions," Paul said on Fox News Channel. "If he launches this little piddly attack with a few cruise missiles, it won't stop chemical weapons, but it may well insight a gas attack on Israelis. I think it's a big mistake.”

Paul said that if military action is undertaken, it should only happen after Congress signs off.

"... We are not excited to get involved in a new war right now," he said. "And so, I would do everything I can to stop the president. We should not engage in a war, and we certainly shouldn't engage in it in an unconstitutional fashion.”

Paul also reiterated that he needed more proof that the Syrian regime actually used chemical weapons.

"I'd like to see the evidence before we go all half-cocked into a war," Paul said.