Atomic scientist Edward Teller, widely known as the "father of the H-bomb", has died at the age of 95. Teller played a key role in US defence and energy policies for more than half a century, championing the development of the atomic and hydrogen bombs. He was also a strong advocate of nuclear power and the Strategic Defense Initiative missile defence system, dubbed "Star Wars". Teller suffered a stroke and died on Tuesday in Stanford, California, near the Hoover Institute where he served as a senior research fellow, a spokesman for Lawrence Livermore Laboratory said. Teller's long career saw him influence the policies of several US presidencies. In 1939, he was one of three scientists who encouraged Albert Einstein to alert President Franklin D. Roosevelt that the power of nuclear fission - the splitting of an atom's nucleus - could be tapped to create a devastating new weapon.