President Obama Monday will announce former Sen. Chuck Hagel as his pick for Secretary of Defense, an administration official said.

A trusted Obama adviser and decorated veteran with respect among many in the miliary, the former Nebraska senator, nevertheless is expected to face considerable scrutiny in the Senate.

Hagel has faced a backlash for past remarks on Israel and gays, though Obama said in a televised interview a week ago that he hadn't seen anything to rule Hagel out. Experts say whoever gets the job will face considerable challenges as military budgets are trimmed.

Log Cabin Republicans have cited a 14-year-old quote to accuse Hagel of being anti-gay and backers of Israel have questioned his support for the country; Neo-conservatives questioned whether he’d be too soft on Iran and Hamas.

Senate Minority Leader Mitch McConnell said Sunday Hagel would undergo "the same kinds of oversight hearings that any nominee for such an important position would expect."

Speaking on Meet the Press, McConnell added that Hagel's views on Israel, Iran and "all the other positions that he's taken over the years" will be up for discussion.

McConnell predicted a "lot of tough questions of Senator Hagel, but he'll be treated fairly by Republicans in the Senate."

A group of former Republican and Democratic officials last week in a letter to Obama vouched for Hagel, saying "no one has been more steadfast in supporting America's commitment to Israel's security than has Senator Hagel."