US President Barack Obama delivers a statement on legislation sent to Congress to authorize the use of military force against the Islamic State from the Roosevelt Room at the White House in Washington February 11, 2015. [Photo/Agencies]

WASHINGTON - US President Barack Obama requested Congress on Wednesday to formally authorize military force against Islamic State (IS) militants, saying the US-led coalition fighting the group is "on the offensive" and the extremist group "is going to lose."

The congressional request doesn't call for the deployment of US ground combat forces to Iraq or Syria and the authorization is limited to three years, Obama said at the White House in a televised statement on his request submitted to Congress earlier in the day.

The proposed legislation "is not the authorization of another ground war like Afghanistan or Iraq," he said. "I'm convinced that the United States should not get dragged back into another prolonged ground war in the Middle East."

But he said that at the same time, the legislation "strikes the necessary balance by giving us the flexibility we need for unforeseen circumstances."

The legislation seeks congressional approval of ground combat operations such as rescuing US or coalition personnel or taking military action against IS leaders. It would also authorize the use of US forces for missions involving intelligence gathering, enabling airstrikes or providing advice and assistance to coalition forces.