Defense Secretary Chuck Hagel says that as the U.S. considers how to expand operations against the Islamic State militants in Iraq, President Barack Obama needs to weigh all the consequences of what could be a lengthy campaign, and what could go wrong.

Speaking to reporters in Turkey Monday, Hagel says the advice he gives the president has to include not just the start of any operation, but how it will end. But he says that's not an argument for inaction.

He says in talks with Congress about Obama's remarks scheduled for Wednesday there has been broad agreement that the Islamic State militants must be destroyed.

He said some lawmakers don't believe Obama needs any more legal authorizations from Congress to broaden the fight. Other members aren't so sure.