Senate Minority Leader Mitch McConnell said Tuesday that he would not support President Barack Obama's proposal for a limited military strike in Syria.
McConnell, who is facing a difficult primary challenge next year, has remained largely silent throughout the Syria debate and is the only major Republican leader to oppose authorizing a strike.
McConnell said he was voting against the bill because he was unconvinced it would stop Syrian President Bashar al-Assad from using chemical weapons again, because it was not a part of a broader strategy to end the country's civil war and because U.S. national security was not directly in jeopardy.
"I'll stand shoulder to shoulder with this president or any other in an case where our vital national security interests are threatened, our treaty allies are attacked or we face an imminent threat" McConnell said.
"I'll be voting against this resolution, a vital national security risk clearly not at play," he added.
McConnell also chided Obama on his foreign policy throughout his presidency.
"It is long passed time the president drop the prose of the reluctant warrior and lead," he said. "You can't build foreign policy on the vilification of your predecessor alone."
McConnell's decision to oppose strikes also puts him in direct conflict with House Speaker John Boehner, a rare division between the party's top two leaders in Congress.
President Obama will give a speech on Syria later tonight.