Washington, December 3 (RHC)-- U.S. President Barack Obama will likely nominate Ashton Carter, a former deputy at the Department of Defense, to lead the Pentagon and succeed the resigning Chuck Hagel, senior U.S. officials say.

Carter, the former No. 2 and No. 3 official at the U.S. Defense Department, is a "leading candidate" for the Pentagon’s top position, three administration officials said Tuesday, all speaking on condition of anonymity because the president's selection is not public. White House officials, however, would not confirm that Carter was Obama's pick.

Carter was the Deputy Secretary of Defense from October 2011 to December 2013, serving as the top deputy to Hagel and his predecessor Leon Panetta. He also served as assistant secretary of defense for international security policy under President Bill Clinton. His specialties include science, technology, and developing the defense budget in tight economic times and has a doctorate in theoretical physics from Oxford University.

Hagel resigned under pressure last week after less than two years as the head of the Defense Department. U.S. officials said privately that he had been forced out. Hagel had expressed frustration over the Obama administration’s strategy in Iraq and Syria. During his time as a senator, Hagel was an outspoken critic of Israel and openly criticized the Bush administration’s foreign policy.

During an interview in 2006, the former Vietnam War veteran stated that "the Jewish lobby intimidates a lot of people [on Capitol Hill]" and "I'm not an Israeli senator; I’m a United States senator.”