WASHINGTON — President Barack Obama has gained ground in his push for Senate ratification of a stalled nuclear treaty as once-reluctant Republicans signaled a willingness to back the pact with Russia.

Lamar Alexander of Tennessee, the No. 3 Republican in the Senate, said today he is “wide open” to supporting the treaty if the administration addresses his concerns about modernization of the remaining U.S. nuclear arsenal.

He praised the White House for working with lawmakers.

“They're making important steps in the right direction,” Alexander said on MSNBC. He said the treaty “has important advantages to our country in terms of the data and the verification.”

The administration jump-started the treaty with a series of steps this week, including outreach by Vice President Joe Biden to lawmakers and the circulation of a letter from the heads of the three U.S. nuclear weapons laboratories expressing support for Obama's 10-year, $84 billion plan to maintain the nuclear stockpile.

Sen. Richard Lugar of Indiana, the top Republican on the Foreign Relations Committee and a proponent of the treaty, distributed the letter to more than a dozen Republican lawmakers at a meeting late Wednesday. Several Republican senators, including Olympia Snowe of Maine and Johnny Isakson of Georgia, emerged from the session more positive about completing the treaty in the lame-duck session.

By The Associated Press