US president Barack Obama has said destroying Islamic State (IS) is his top priority.
Mr Obama said the battle with the extremist group remains a difficult fight, but expressed confidence in victory.
He said IS continues to lose ground in its strongholds in Iraq and Syria, and is being squeezed financially.
Mr Obama added: "We are going to squeeze them and we will defeat them."
The US leader commented at a White House meeting with the Joint Chiefs of Staff and the combatant commanders.
He pledged a review of defence strategies and the spending to carry them out. Mr Obama added that the meeting is also a chance to thank US service members for their sacrifices.
Mr Obama, his wife Michelle and vice president Joe Biden are also hosting a White House dinner for the military leaders.