Richard Holbrooke, the US envoy to Afghanistan and Pakistan,critically ill.

The US envoy To Afghanistan and Pakistan was admitted to hospital on Friday in a critical condition. He has undergone surgery to repair his aorta.

He is best known for Dayton peace in 1995, which ended the the Bosnian War.

President Barack Obama named Mr Holbrooke as his special representative to Afghanistan and Pakistan in January 2009.

Mr Barak Hussain Obama describing him as a "tireless public servant" and a "towering figure in American foreign policy".

"We continue to pray for his recovery, and support his family in this difficult time," Mr Obama said.

Mr Holbrooke was working at the State Department when he was taken ill.

In a brief statement released on Saturday, State Department spokesman PJ Crowley said: "This morning, doctors completed surgery to repair a tear in his aorta. He is in critical condition and has been joined by his family".

The aorta is the largest artery in the human body and carries oxygenated blood from the heart.