U.S. scientist Edward Teller dubbed 'father of the H-Bomb' has died in California.

Teller, 95, played a key role in U.S. defence and energy policies for more than half a century.

He was given his nickname because he championed the development of the atomic and hydrogen bombs, and nuclear power. He was also a strong proponent of the national missile defence system known as "Star Wars."

Teller also will be remembered for his role in destroying the career of his one-time boss, Robert Oppenheimer.

Teller attacked Oppenheimer, who had directed the Manhattan Project, claiming he had slowed development of the atomic bomb, allowing the Soviet Union to catch up. Oppenheimer was then frozen out of any government work.

Teller suffered a stroke in his home on the campus of Stanford University in California.