White House Official: Richard Holbrooke ‘Tough and Resilient’

A White House official has called U.S. diplomat Richard Holbrooke "tough and resilient," as the special envoy struggles to recover from emergency heart surgery.

Presidential adviser David Axelrod said on U.S. television Sunday that he and his colleagues are praying that those qualities help Holbrooke survive.

Holbrooke, the U.S. envoy to Afghanistan and Pakistan, is in critical condition after more than 20 hours of surgery to fix a tear in the large artery that moves blood from his heart. Doctors completed the operation early Saturday.

U.S. President Barack Obama issued a statement Saturday evening saying he and the first lady are praying for Holbrooke, whom the president called a "towering figure in American foreign policy."

The 69-year-old diplomat previously served as U.S. ambassador to the United Nations and was the chief architect of the 1995 Dayton Peace Accords that ended the war in Bosnia-Herzegovina.

Holbrooke was hospitalized Friday after collapsing during a meeting with U.S. Secretary of State Hillary Clinton at the State Department in Washington.