Former US Secretary of State Henry Kissinger has died at the age 100.

He served as America's top diplomat and national security adviser during the Nixon and Ford administrations.

In a statement, Kissinger Associates, a political consulting firm he founded, said the German-born former diplomat died at his home in Connecticut.

During his decades-long career, Mr Kissinger played a key, and sometimes controversial, role in US foreign and security policy.

The statement from Kissinger Associates did not give a cause of death.

Born in Germany in 1923, Kissinger first came to the US in 1938 when his family fled Nazi Germany.

• Henry Kissinger: Diplomat who towered over world affairs

He became a US citizen in 1943 and went on to serve three years in the US Army and later in the Counter Intelligence Corps.

After earning bachelor's, master's, and PhD degrees, he taught international relations at Harvard.

In 1969, then-President Richard Nixon appointed him National Security Adviser, a position which gave him enormous influence over US foreign policy.

As secretary of state during the Nixon administration - and later under President Gerald Ford - Mr Kissinger led diplomatic efforts towards China, helped negotiate an end to the 1973 Yom Kippur War between Israel and its neighbours and was instrumental in the Paris Peace Accords that ended the Vietnam War.

Over the years, however, Kissinger was also subject to scathing criticism from those who accused him of putting rivalry with the Soviet Union over human rights and supporting repressive regimes across the world, including Augusto Pinochet's regime in Chile.

In 1973, he was awarded a Nobel Peace Prize alongside North Vietnam's Le Duc Tho, who refused to accept.

The controversial award led to two members of the Nobel committee resigning.