The U.S. will use a NATO summit next week to push for a coalition of countries to beat back Islamic State militants in Syria and Iraq.br br That's according to U.S. Secretary of State John Kerry, writing in a New York Times opinion piece on Saturday.br br But leading Republicans criticize President Barack Obama for not having a concrete plan in place yet over the militant threat in Syria.br br Republican Arizona Senator John McCain, speaking on the CBS news program Face the Nation, said the president is either "in denial or overwhelmed" by the Islamic State.br br He criticized the president's decision not to move against the threat of militants in Syria two years ago.