World powers and Iran launched a new round of negotiations in Istanbul on Saturday, April 14, aiming to resolve a long-standing dispute over Tehran's nuclear program that threatens to spark a new war in the Middle East.

"Delegates have gone in... plenary is just getting started," Reuters quoted a diplomat close to the negotiations as saying.

Diplomats say the round, the first in 15 months, is unlikely to result in a major breakthrough but offers a chance to resume dialogue and dampen speculation that Israel might launch military strikes to prevent its arch enemy from acquiring nuclear arms.

Global fuel prices have risen this year amid deepening tensions over the nuclear program, which Iran says is for peaceful purposes.