Lieberman: Obama should commit to modernizing nukes to win Senate votes

President Barack Obama must commit to making sure the U.S. has an effective nuclear stockpile in order to win ratification for his new arms reduction treaty, Sen. Joe Lieberman (I-Conn.) said Monday.

Lieberman, the chairman of the Senate Homeland Security Committee, said that he and his Senate colleagues would be wary of voting to ratify the treaty Obama signed last week with Russian President Dmitry Medvedev to reduce each nation's nuclear arsenal.

"I hope I can support ratification of the treaty, but I'm not there yet," Lieberman said Monday during an appearance on MSNBC. "But as we reduce the number of nuclear warheads ... I think we've got to make sure that the remaining nuclear warheads work."

The Senate needs 67 votes to ratify a treaty, higher than the 60 votes normally needed to end debate on a measure. With 59 Democrats in the Senate, at least eight Republicans would need to sign on to supporting the treaty, assuming all Democrats decide to back it.

Lieberman said that he was aware of a debate within the Obama administration internally over whether or not they would commit to modernizing the U.S. nuclear arsenal, a commitment that the centrist senator said could be key to locking up the necessary votes.

"I've talked to some colleagues and I don't think there's going to be 67 votes for the START Treaty unless there's a clear commitment to making sure our nuclear stockpile is still working," he said.

As senators begin mulling the treaty, world leaders and diplomats have descended on Washington for a nuclear arms security summit.