Richard Holbrooke, a top U.S. diplomat who was a key figure in negotiating peace to end the war in Bosnia 15 years ago, and was the special envoy to Afghanistan and Pakistan, died on Monday.

Holbrooke, 69, served at the State Department over a span of nearly 50 years, mainly serving in Europe and Asia. He died in Washington D.C. after failing to recuperate following surgery to repair a tear in his aorta.

President Barack Obama said he was deeply saddened by his passing and called him a true giant of American foreign policy who has made America stronger, safer, and more respected.

Holbrooke had been managing diplomatic relations between the U.S., Afghanistan and Pakistan, engaging with political and military leaders in the region amid the current war.

In 1995, serving under then Secretary of State Warren Christopher, Holbrooke was considered the chief architect of the Dayton Peace Accords, which involved Bosnia, Herzegovina and Croatia. The deal ended three and a half years of conflict.

I pay tribute to his diplomatic skills, strategic vision and legendary determination. As the architect of the 1995 Dayton Agreement, Ambassador Holbrooke played a key role in ending the war in Bosnia, the most terrible tragedy on European soil since  World War II, said NATO Secretary General Anders Fogh Rasmussen. 

Ongoing conflicts in the formerly unified Yugoslavia brought Holbrooke back to the region in 1999. As a special envoy, Holbrooke was sent to warn Yugoslavian President Slobodan Milosevic to accept a peace agreement for Kosovo to avoid bombing by NATO.

He was the consummate diplomat, able to stare down dictators and stand up for America's interests and values even under the most difficult circumstances, Secretary of State Hillary Clinton said. She said the U.S. has lost one of its fiercest champions.

Holbrooke's career  began in 1962, where he started out as a civilian representative in Vietnam during the war, eventually rising to become a junior diplomat and assisting in reaching agreements to help end the war.

After a stint as a Peace Corps director in Morroco during the seventies, he left to become a managing editor at Foreign Policy magazine. In the Carter administration, he oversaw the normalization of relations with China.

His diplomatic career briefly ended in the 1980s when he became a senior advisor and later an executive at Wall Street firm Lehman Brothers.

During the Clinton administration, he served as U.S. ambassador to Germany. Other career highlights included a role as U.N. Ambassador.

He served as an executive in the private equity firm Perseus LLC in the early 2000s and as a board member of insurer AIG for several years before being appointed special envoy by President Obama in 2009.

He is survived by his wife Kati, his sons David and Anthony, and his step-children Elizabeth and Chris Jennings.