U.S. Defense Secretary Robert Gates warned on Sunday that it will complicate the consensus around the UN Security Council resolution on no-fly zone over Libya if there is an attempt to expand the goals of military strikes against the North African nation.

Speaking onboard a plane enroute to Russia, the Pentagon chief said he thinks "it's important that we operate within the mandate of the UN Security Council resolution."

Gates said most nations in the region want to see Libya remain a unified state, and cautioned against getting too involved in the internal conflict of that country.

He also said the United States expects to turn over control of the military mission against Libya to a coalition "in a matter of days."

Gates departed Washington Sunday afternoon to visit Russia, probably his last visit to that country as head of the Pentagon.