The Brookings Institution has announced the Ambassador Thomas Pickering has joined the think tank as a distinguished senior fellow.

Pickering will work under the Brookings Foreign Policy program.

“We are honored that Ambassador Pickering has agreed to join Brookings and look forward to calling on his vast foreign policy expertise,” said Brookings president Strobe Talbott in a released statement. “I am sure that Tom’s many years of outstanding public service as a leading U.S. diplomat will further the Institution’s global agenda.”

Pickering retired from the State Department after 40 years of service that included U.S. ambassador to the Russian Federation, India, Israel and Jordan. In 1997, Pickering returned to the State Department, having been named under secretary of state for political affairs, the number three position within the State Department.

He also served as U.S. ambassador the United Nations from 1989 to 1992.

Pickering most recently served as vice chair of Hills and Company, an international consulting firm.