Democratic US Senator John Kerry said Wednesday he was optimistic that the US Senate will ratify a landmark nuclear weapons deal with Russia before the end of the year.

"I'm very hopeful," Kerry, who chairs the Senate Foreign Relations Committee, told reporters on a conference call from Israel when asked about new Strategic Arms Reduction Treaty (START).

"We're going to try to move to the START treaty and we're going to get the START treaty done," he said.

Kerry indicated it was "likely" that the Senate, which returns to Washington next week for a "lame-duck" session after key elections last week, would take up the accord in December.

He also said he had been in touch with the top Republican on his committee, Senator Richard Lugar, as well as Secretary of State Hillary Clinton, Vice President Joe Biden, and a leading critic of the accord, Republican Senator John Kyl.

The START treaty -- signed by Russian President Dmitry Medvedev and Obama at an elaborate ceremony in Prague in April -- restricts each nation to a maximum of 1,550 deployed warheads, a cut of about 30 percent from a limit set in 2002.

The agreement, a top Obama foreign policy initiative, replaces a previous accord that lapsed in December 2009 and also requires ratification by Russia's lower house, the Duma.

US Senate ratification requires 67 votes, meaning Obama's Democratic allies will need to pick up considerable Republican support.

Republicans, including Kyl, have said they need to be sure that the US nuclear arsenal will be modernized and that the treaty will not hamper US missile defense efforts.