Leaders in the US and elsewhere have paid tribute to veteran US diplomat Richard Holbrooke, the Obama administration's special envoy to Afghanistan and Pakistan, who has died aged 69.
Barack Obama, US President
He was a truly unique figure who will be remembered for his tireless diplomacy, love of country and pursuit of peace.
The progress that we have made in Afghanistan and Pakistan is due in no small measure to Richard's relentless focus on America's national interest and pursuit of peace and security. He understood, in his life and his work, that our interests encompassed the values that we hold so dear.
Hillary Clinton, US Secretary of State
Tonight America has lost one of its fiercest champions and most dedicated public servants. Richard Holbrooke served the country he loved for nearly half a century, representing the United States in far-flung war-zones and high-level peace talks, always with distinctive brilliance and unmatched determination. He was one of a kind - a true statesman - and that makes his passing all the more painful.
From his early days in Vietnam to his historic role bringing peace to the Balkans to his last mission in Afghanistan and Pakistan, Richard helped shape our history, manage our perilous present, and secure our future. 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.
Bill Clinton, former US President
In a lifetime of passionate, brilliant service on the front lines of war and peace, freedom and oppression, Richard Holbrooke saved lives, secured peace, and restored hope for countless people around the world. Tomorrow marks the 15-year anniversary of the signing of the Dayton Accords - the agreement Dick negotiated which stopped the killings in Bosnia and paved a path to peace in the Balkans that endures today.
For the last two years, he worked hard to counter terrorism and to build a secure, democratic future for Afghanistan and Pakistan. Our nation is safer, and our world stronger, because of the work he did.
Asif Ali Zardari, Pakistani President
Pakistan has lost a friend. He was an accomplished and experienced diplomat who quickly gained the confidence of his interlocutors. He was a key player in international diplomacy to bring peace to Bosnia and in confronting militancy in our part of the world.
His services will be long remembered. The best tribute to him is to reiterate our resolve to root out extremism and usher in peace.
Hamid Karzai, Afghan President (statement from spokesman's office)
While saddened by the news, President Karzai said Ambassador Holbrooke was a veteran and seasoned diplomat who had served greatly the government and the people of the United States.
General David Petraeus, US commander in Afghanistan
This is a tragic loss for our country, this region and our world.
Mr Holbrooke was a true titan in the diplomatic arena and a central figure in the effort in Afghanistan and Pakistan.
Qari Yousuf Ahmadi, Taliban spokesman
Rumours have it that this giant of American politics and diplomacy became ill with heart disease when his previous fame and credibility came under question after the unremitting failures of the mission of Afghanistan... The protracted Afghan war and the descending trajectory of the Americans' handling of the warfare in the country had had a lethal dent on Holbrooke's health as a high-ranking American official. He was grappling with a constant psychological stress.
Emergence of this untoward phenomenon as an offshoot of the Afghan issue is not now a strange thing. The same was the case with the former Soviet Union as the crisis touched its climax. Former Soviet leaders [Leonid] Brezhnev, Konstantin Chernenko and [Yuri] Andropov had heart attacks... They relieved themselves of the hard task of the Afghan mission by retreating into the lap of death...
Holbrooke's timely death could have a didactic effect on the American strategists... Their formulation of new military strategies will never change the imminent defeat into a victory...
Baroness Ashton, EU foreign policy chief
A remarkable man, a true diplomat and a champion of peace and reconciliation, not just in Pakistan and Afghanistan but throughout the world in nearly half a century of service to his country and the international community. Europe will in particular remember his historic role in bringing peace to the Balkans. I am proud to have known Richard and privileged to have been his friend.
Anders Fogh Rasmussen, Nato Secretary General
I pay tribute to his diplomatic skills, strategic vision and legendary determination. He knew that history is unpredictable; that we sometimes have to defend our security by facing conflicts in distant places; and that the transatlantic alliance remains indispensable.
Gen Bill Nash, retired US general who worked closely with Holbrooke in the Balkans
He had significant experience for many, many years working on the hardest problems. I mean, you talk about the Balkans, but you really have to go back to Vietnam where he was a young foreign service officer who was very involved in trying to build a civil society and help the government of south Vietnam provide public services to their citizens.
His characteristics - he was a force of nature, he was a man of great intellect but he was also a very powerful leader. He had a way of setting the stage and bringing all the players together and setting the conditions to achieve his objectives [which] were to pursue the benefit of mankind but also the United States.
Haris Silajdzic, wartime Bosnian foreign minister
He was instrumental in bringing peace to Bosnia. An unjust peace, but still a peace.
Peter Robinson, lawyer for former Bosnian Serb leader Radovan Karadzic, who is currently on trial for war crimes and claims Holbrooke promised him immunity from prosecution
Dr Karadzic notes with sadness and regret the passing of Richard Holbrooke.
David Cameron, UK Prime Minister
He was a formidable force of American diplomacy - an indefatigable champion in the cause of peace, who worked tirelessly for a better world.
Most recently his energies were devoted to finding a peaceful way forward for Afghanistan and her people. But he will always be remembered for his pre-eminent role in ending the vicious war in Bosnia, where his force of personality and his negotiating skill combined to drive through the Dayton peace agreement and put a halt to the fighting.
He was a true public servant who will be greatly missed.
William Hague, UK Foreign Secretary
Ambassador Holbrooke was truly one of the best and the brightest of his generation. Whether as a young state department officer in Vietnam or as ambassador to Germany and the UN, he has served his nation with distinction and integrity.
Since I started in the job of foreign secretary, I have worked closely with Ambassador Holbrooke.... his work will continue.
Tony Blair, former UK Prime Minister
He was a remarkable man, a remarkable public servant and someone who contributed enormously to the cause of a more peaceful and just world. He will be deeply mourned by many people in many different nations.
John Kerry, US Senate Foreign Relations Committee chairman
He was always a man on a mission, the toughest mission, and that mission was waging peace through tough-as-nails, never-quit diplomacy - and Richard's life's work saved tens of thousands of lives.
It is almost a bittersweet bookend that a career of public diplomacy that began trying to save a war gone wrong now ends with a valiant effort to keep another war from going wrong.
Peter Galbraith, former US ambassador and UN official
He was in a category by himself. Someone who was very strategic, he knew where he wanted to go, and he had a good understanding as a diplomat of the different players and how actually to relate to them. But [he was] an operator with a real moral sense - he didn't have to get involved in Bosnia, he wanted to. And he did it because he was outraged by what was going on.