John Kerry, en route to Geneva
John Kerry, en route to GenevaFlash90

The deal struck Sunday between Iran and world powers will help - not hurt - Israel's security, US Secretary of State John Kerry insisted Sunday morning to AFP

"The comprehensive agreement will make the world safer ... and Israel safer," Kerry told reporters.

Ahead of the deal, Israel had issued repeated warnings that any easing of sanctions against Iran could enable it to acquire atomic weapons. Prime Minister Binyamin Netanyahu has called the deal "a bad deal" and has publicly kept the option of a strike on a nuclear Iran open - with Israeli public support. 

Kerry said Netanyahu -- "a friend of mine" -- had been kept abreast of the state of play in the talks, which kicked off Wednesday."I talk to him several times a week," he said. "I talked to him in the last day about this very issue."

Regarding the falling out between the US and Israel, which developed over the last several weeks due in part to this issue, Kerry insisted that any differences between them were simply a matter of "judgement" and "calculation." 

"There is no difference whatsoever between the US and Israel of what the end goal is -- that Iran will not have a nuclear weapon," Kerry insisted. 

Throwing the ball into Tehran's court, Kerry said it should be a simple matter for Iran to prove its critics wrong. "It ought to be really easy to do the things that other nations do that enrich," he said. "To prove it."

Iran has consistently declared that it will never give up on its right to enrich uranium, though Foreign Minister Mohammad Javad Zarif said last week that Iran would not insist that others recognize this right.