A six-term congressman from Indiana, the 52-year-old Roemer is known for his moderate, bipartisan politics and national security experience. He will succeed David Mulford, who played a key role in pushing the India-US nuclear deal during the second term of the George W. Bush presidency.

An expert on non-proliferation and weapons of mass destruction, Roemer, a former member of the 9/11 Commission, is said to be close to President Barack Obama. Roemer now serves on the Commission on the Prevention of Weapons of Mass Destruction, Proliferation and Terrorism.