WASHINGTON — Top Senate Republicans said Tuesday they will reserve judgment on Chuck Hagel’s nomination until after his confirmation hearing next week, a positive sign for President Barack Obama’s choice to head the Defense Department.

Hagel, who already has drawn strong opposition from six Senate Republicans, continued his outreach to lawmakers on Tuesday, meeting with Sen. John McCain, whose support for the nomination could smooth the way for the former GOP senator and provide political cover for other Republicans to back the nominee.

“Sen. Hagel and I are old friends, and we had a very frank and candid conversation, and I’ll be looking forward to the hearing and asking him questions,” the Arizona Republican told reporters at a news conference on his recent overseas trip. “He should be given the opportunity of a hearing before any of us makes a judgment.”

Hagel, during a brief conversation with reporters in the Capitol, declined to answer specific questions, simply saying, “we have a hearing next week, and I look forward to answering questions.”

Sen. Carl Levin, D-Mich., the chairman of the Senate Armed Services Committee, said earlier in the day that it is too soon to count the votes and he will have a better assessment of the support for Hagel after his confirmation hearing on Jan. 31. Asked whether there were any Republican votes for Hagel, Levin said: “I haven’t seen any, but there may be that I haven’t seen. That doesn’t mean that there won’t be.”

The Hagel nominationgained momentum last week as Sens. Charles Schumer, D-N.Y., and Barbara Boxer, D-Calif., two of the strongest pro-Israel Democrats in the Senate, said the former Nebraska senator had addressed their concerns about his stand on Iran sanctions and support for Israel.

But Hagel still faces ambivalence among Republicans, if not outright opposition. Sen. Jim Inhofe of Oklahoma, the panel’s top Republican, has announced his opposition as have several other committee members. Hagel was to meet today with Sen. Kelly Ayotte, R-N.H., a committee member who has said she was perplexed by the nomination.

Another panel member, Sen. Saxby Chambliss, R-Ga., said Tuesday: “I look forward to visiting with him and hearing his testimony, and we’ll see where it goes.”

Concerns about Hagel replacing Defense Secretary Leon Panetta have centered on whether he is sufficiently pro-Israel, his description of pro-Israel groups as a “Jewish lobby” and his stand on gay rights. Some GOP lawmakers also are concerned about potential cuts to defense spending and Hagel’s past support for reductions in nuclear weapons.

“That’s of great importance to me,” said Sen. Bob Corker of Tennessee, the top Republican on the Senate Foreign Relations Committee. Corker’s state is home to the Y-12 nuclear facility and significant cuts in the nuclear arsenal would affect his state.

“I want to delve beyond the one-liners and sentences that have been brought forth by groups. It’ll be a very earnest conversation. I always start with an open mind. But I do have concerns,” said Corker, who is scheduled to meet with Hagel on Friday.

Democrats hold a 55-45 advantage in the Senate and would have the votes to confirm Hagel on a simple majority, but they would need five Republican votes for the 60-vote threshold to break a GOP filibuster.

Separately, a GOP-leaning group launched an anti-Hagel ad campaign in the home states of five Senate Democrats up for re-election next year.

Information for this article was contributed by Richard Lardner of The Associated Press and by Brian Wingfield, Jeff Plungis, David Ellis and Angela Greiling Keane of Bloomberg News.

Front Section, Pages 2 on 01/23/2013