Former US vice president Dick Cheney has accused President Barack Obama of "trying to pretend we are not at war" with terrorists in the wake of the Christmas Day attack on a US airliner, according to dpa. In a statement to Politico published Wednesday, Cheney said Obama"s policies have sought to cast aside the realities of the war on terrorism by taking a "low key" response to an attack, suspected of being carried out by a Nigerian citizen with al-Qaeda ties. "As I"ve watched the events of the last few days it is clear once again that President Obama is trying to pretend we are not at war," Cheney said. "He seems to think if he has a low key response to an attempt to blow up an airliner and kill hundreds of people we won"t be at war." Cheney has been a leading Republican critic of Obama since he and former president George W Bush left office in January, and his remarks are intended to show that Obama and the Democrats are weak when to comes to fighting terrorism. Cheney cited the administration"s decision to try the five alleged plotters of the September 11, 2001 terrorist attacks in a civilian rather than military court, and to close the Guantanamo Bay prison facility. The suspect on the Delta/Northwest Airlines flight, Umar Farouk Abdulmutallab, remains in US custody after he allegedly tried to detonate explosive as the plane was preparing to land in Detroit. Abdulmutallab has reportedly told US authorities he received the explosives and training from al-Qaeda elements in Yemen, which announced it is investing ties between the Nigerian and the terrorist group. Meanwhile, CNN, citing two Obama administration officials, reported the military has begun to assess possible targets in Yemen for retaliatory strikes against al-Qaeda. Al-Qaeda in the Arabian Peninsula, or AQAP, released a statement earlier this week taking responsibility for the failed attack and warned more are on the way. AQAP said the airline plot was meant to avenge US assistance to the Yemeni government, which has been launching assaults against al-Qaeda militants in the country. The United States has reportedly provided intelligence to assist with air raids, and is believed to also be conducting covert operations in Yemen against al-Qaeda.