Israeli Prime Minister Benjamin Netanyahu urged the international community on Wednesday to threaten Iran with "military sanctions", saying economic measures are failing to curb Tehran's nuclear drive.

"I believe it is incumbent upon the international community to intensify the sanctions and clarify that if Iran continues its programme, there will be military sanctions," Netanyahu said.

He did not, in a statement released by the prime minister's office, specify what military measures he envisages.

"I don't think there are any other means that will make Iran heed the international community's demands," he said, in his first remarks on the issue after two days of nuclear talks between Tehran and world powers in the Kazakh city of Almaty.

Netanyahu has long said that only a credible military threat, coupled with tough economic sanctions, could dissuade Iran from acquiring what Israel and the West believe is a capability to build atomic weapons.

Iran says it is enriching uranium for peaceful purposes only.

In Almaty, the first negotiations between Iran and six world powers in eight months ended without a breakthrough on Wednesday. They agreed to meet again at expert level in Istanbul next month and resume political talks in Kazakhstan on April 5.

Israel, widely believed to be the Middle East's only nuclear-armed power, has strongly hinted it might attack Iran if diplomacy and sanctions fail to halt its nuclear programme.

Netanyahu, setting a "red line" at the United Nations last September, has said Iran could by the middle of this year reach the point where it has enriched enough uranium to move quickly toward building an atomic bomb.