Britain on Monday proposed expanding a United Nations Security Council mandate for a European naval operation to allow it to crack down on arms smuggling in the high seas off war-torn Libya, though Russia voiced concerns about the idea.

Britain circulated a draft resolution to approve the measure to the 15-member council, diplomats said. In October, the council authorized the European naval operation to seize and dispose of boats operated by human traffickers.

"Now once again, we are asking this council to adopt a resolution on authorizing Operation Sophia to enforce the U.N. arms embargo on the high seas off the coast of Libya," European Union foreign policy chief Federica Mogherini told the council.