Vice President Joseph Biden met with Senate Foreign Relations Chairman John Kerry (D-Mass.) on Monday to map out a strategy for passing the Strategic Arms Reduction Treaty, but they still face a heavy lift overcoming resistance from key Republicans.

Biden is spearheading the administration’s efforts to ratify the arms deal with Russia, which President Barack Obama has deemed a priority for the lame-duck Congress.

“Chairman Kerry is committed to working with his colleagues and the administration to bring this treaty to a vote in the Senate before the end of the year,” a Kerry spokesman said.

The White House has been scrambling to lure GOP allies on START and lobbying individual Senators for support. But Obama was dealt a blow last week when Minority Whip Jon Kyl (R-Ariz.) announced his opposition to dealing with the treaty during the lame-duck session, citing a crowded agenda. Sen. George Voinovich (R-Ohio) has also signaled an unwillingness to moving on the treaty this year.

White House Press Secretary Robert Gibbs hinted Monday that Republicans are holding up START for political reasons, something he said should have no role in the matter given the string of endorsements for START ratification that came from NATO allies over the weekend. Obama secured international support for the treaty during a weekend trip to Lisbon, Portugal, for a NATO meeting.

“Given who you’ve seen in terms of validaters and supporters of this treaty, that doesn’t fit the mold of what you normally see in a political issue. And we don’t think it should fit that mold, given who those supporters are,” Gibbs said during a briefing.

“We think this is something that can and should get done over the course of the next several weeks and certainly before the end of the year,” he added.