House Speaker John Boehner, R-Ohio, reiterated his support for President Obama's plan to intervene militarily in Syria on Tuesday, asking members to provide a "united front" with the president on a critical foreign policy issue.

"I've supported every president that I've served under over the last 23 years on the use of military force. There's one person that speaks for the United States of America when it comes to foreign policy, and that's the president of the United States," Boehner said at a Capitol press conference. He said it is "critical" that his GOP colleagues support the president.

The speaker also indicated he was "somewhat skeptical" of a Russian plan to confiscate Syrian chemical weapons, a move many are hoping would allow the U.S. to avoid a military intervention.

"Diplomacy is always a better outcome than military action," the Republican speaker said. "But I will say I am somewhat skeptical of the actors involved."

The president will make a prime-time address to the nation on the situation in Syria at 9 p.m. on Tuesday.

Despite the support of Boehner and House Majority Leader Eric Cantor, many congressional Republicans have been reluctant to support military action. Senate Minority Leader Mitch McConnell, R-Ky., who faces a tough re-election fight next year, said Tuesday that he opposes intervention, making him the only congressional leader in either party to break with Obama.

Boehner acknowledged that a "war weary" American public wasn't eager to intervene in another Middle Eastern country and made that clear to lawmakers.

"Clearly members tend to reflect their constituents," he said. "The American people are not yet supportive. ... That's why I think [Obama's address] is so important."