The White House said the forces will join an already 3,100-strong mission to "train, advise and assist" the Iraqi army as well as Sunni tribal fighters.
The new contingent will focus on efforts to wrest back control of provincial capital Ramadi.
Islamic State seized the predominately Sunni city near Baghdad in May, punching a giant hole in Obama's strategy to "defeat and degrade" the jihadist group. (READ MORE)
