Edward Teller, the molecular physicist dubbed the "father of the H-bomb" for his role in the early development of nuclear weapons, has died aged 95.
A spokeswoman for the Stanford University news service, said Teller had suffered a stroke earlier this weekand died at his home on the university campus yesterday.
A naturalized US citizen born in Hungary, Teller was akey member of a group of top scientists who fled Hitler's Germany and ended up working on the Manhattan Project, the secret program that developed the atomic bomb.
After the war, Teller pressed the case for a continuedstrong national defense, persuading President Harry Truman of the need for the far more powerful hydrogen bomb.
The United States detonated the first H-bomb on the Pacific atoll of Eniwetok in November 1952. It was 2,500 times more powerful than the atomic weapons dropped on Hiroshima and Nagasaki in 1945, which prompted Japan's surrender and brought World War II to a close.
"It wasn't a choice. Nuclear energy existed," Teller told a newspaper interviewer shortly before his 80th birthday.
"We would have found it no matter what we did. It's sheer arrogance to say we created the bomb."
Earlier in his career Teller also taught physics and helped set up a graduate department in applied sciences at the University of California.
"Edward Teller was one of the world's leading scientificminds of the 20th century, and he made a major contribution to the security of our nation and world peace," University of California President Richard C. Atkinson said.
Teller, who worked right up to the time of his death, was a senior research fellow at the Hoover Institution at Stanford, specializing in defense and energy policy.
Born in Budapest in 1908, he completed his Ph.D. inphysics under Werner Heisenberg in 1930 at the University of Leipzig and did post-graduate work in Copenhagen with pioneering Danish nuclear physicist Neils Bohr.