Lawrence Eagleburger, briefly US secretary of state under President George Bush senior, has died aged 80.He also served as Mr Bush's main adviser on a disintegrating Yugoslavia and played an important role in diplomacy in the first Gulf war.
Mr Eagleburger gained a reputation for straight talking and disentangling complex foreign policy problems.
US President Barack Obama said the US had lost a distinguished diplomat and public servant.
"Through more than four decades of service, first in the army and then as a dedicated foreign service officer and statesman, Lawrence Eagleburger devoted his life to the security of our nation and to strengthening our ties with allies and partners," he said in a statement.
Mr Eagleburger died in Charlottesville, Virginia after a short illness, a friend said.
Born in 1930 in Milwaukee, Wisconsin, he spent 27 years in the foreign service, occupying senior state department positions in the Nixon and Reagan administrations.
In 1989 he became Secretary of State James Baker's deputy, and took over his job in the summer of 1992 when Mr Baker resigned to work for President Bush's unsuccessful re-election campaign.
Mr Eagleburger was the first and so far only career foreign service officer to hold the post.
Under President Jimmy Carter he had been ambassador to Yugoslavia, and he took on a key role as the country descended into conflict in the early 1990s. He was seen by many as pro-Serbian.
Mr Bush described him as "one of the most capable and respected diplomats our foreign service ever produced, and I will be ever grateful for his wise, no-nonsense counsel during those four years of historic change in our world".
He added that during the 1991 first Gulf war Mr Eagleburger was sent to calm Israel when Iraqi leader Saddam Hussein began bombarding it with Scud missiles.
"His performance was nothing short of heroic," Mr Bush said.
Current Secretary of State Hillary Clinton said Mr Eagleburger had been a "strong voice and stalwart champion of America's interests".