WASHINGTON (AFP) - The United States is not ruling out any unilateral move against Islamic militants in northern Mali, but is supporting an African-led bid to oust the rebels, a top US official said Wednesday.

"I am obviously not gonna rule anything in or out here, but our focus in Mali is on the ECOWAS effort," State Department spokeswoman Victoria Nuland said when asked about the possibility of US unilateral action. She reiterated US concerns about the militants spreading terror in the region.