Retired Marine Gen. John Allen will take over as the new president of the Brookings Institution next month, the think tank announced Wednesday.

Allen commanded U.S.-led forces in Afghanistan as a Marine Corps general under President Barack Obama and is currently a foreign policy fellow at the think tank who has focused on the wars in Iraq and Afghanistan as well as the fight against the Islamic State.

The retired general delivered a thunderous speech at last summer's Democratic National Convention in support of nominee Hillary Clinton.

"I am joined by my fellow generals and admirals, and with these magnificent young veterans of Iraq and Afghanistan. They went there and risked their lives because they love this country," he told the crowd. "We trust her judgment. We believe in her vision for a united America. With her as our commander in chief, America will continue to lead in this volatile world."

He will take the reins of the D.C.-based think tank from Strobe Talbott, a long-time Washington hand who has served at the State Department and worked as a journalist at Time magazine. Talbott, who served at Brookings for 15 years, will stay on as foreign policy senior fellow.

"Brookings is home to some of the brightest minds addressing the most pressing issues we face today, including economic and domestic challenges, as well as foreign policy and national security matters, and I am looking forward to working with them to advance the mission of the Brookings Institution," Allen said in a statement.

He called Talbott an "American icon."