Iraq has formally requested that the United States launch air strikes, including drone attacks, against jihadist militants who have seized several key cities and provide more surveillance. "We have a request from the Iraqi government for air power," confirmed top US military commander Gen Martin Dempsey Wednesday. The announcement came after a jihadist attack on Iraq's biggest oil refinery in Baiji north of Baghdad. US President Barack Obama is due to discuss the Iraq crisis with senior Congress members on Wednesday. Gen Dempsey told a Senate panel that it was in America's "national interest to counter [ISIS] wherever we find them".