Chuck Hagel, President Barack Obama’s pick to become the next US defense secretary, has begun calling critics in the Senate in an attempt to clarify his views about how to deal with Iran, Hezbollah and Hamas before his upcoming nomination hearing. …

Hagel’s private calls to lawmakers and efforts by supporters to defend him publicly are part of what is likely to be a hard-fought battle over his nomination. Opponents tried for weeks to dissuade Obama from choosing the former Nebraska senator. …

US officials who have spoken with Hagel since he was nominated on Monday say he has been calling senators before confirmation hearings begin in the coming weeks. Current and former US officials say he is particularly concerned with portrayals of his record on Iran. Critics accuse him of opposing sanctions and being satisfied with containing Tehran, as opposed to preventing it from obtaining a nuclear weapon.