( CNN ) -- The decision to increase U.S. troop deployments to Iraq is n't a sign the U.S. strategy against ISIS is failing , but rather a signal the campaign is entering a new phase , President Barack Obama said in an interview broadcast Sunday on the CBS news program `` Face the Nation . '' The additional 1,500 troops are being sent to help train Iraqi army soldiers and militia fighters to battle ISIS on the ground after weeks of U.S. and allied airstrikes . `` The airstrikes have been very effective in degrading ISIL 's capabilities and slowing the advance that they were making , '' Obama told the show . `` Now what we need is ground troops , Iraqi ground troops , that can start pushing them back . '' ISIL is another acronym for ISIS . U.S. forces will not go into combat , Obama said , reiterating previous promises that there wo n't be a U.S. ground role in the fighting . But , he said , the United States will provide local troops with `` close air support '' once they are ready to go on the offensive against ISIS .
NEW : Obama to send in more troops reflects new phase in ISIS fight , Obama says . CBS : ` ` Now what we need is ground troops , Iraqi ground troops , '' Obama tells CBS . NEW : Obama on America 's role in Iraq : ` ` Do n't mess with us . We 're not here to mess with you '' More death in Iraq as government bombs kill 21 in ISIS - controlled town .