Israeli Prime Minister Benjamin Netanyahu has again warned the world how much more dangerous he thinks Iran is than the Islamic State (ISIS) group.

Meeting with U.S. Sen. Bill Cassidy, D-La., during a visit to Israel, Netanyahu said on Tuesday that a nuclear-armed Iran would be a "thousand times more dangerous and more destructive" than the Islamic State group, reported AFP.

"As horrific as ISIS is, once Iran, the preeminent terrorist state of our time, acquires nuclear weapons, it will be a hundred times more dangerous, a thousand times more dangerous and more destructive than ISIS," Netanyahu said.

The warning comes as representatives from Iran and the P5+1 nations started a new round of talks in the Austrian capital of Vienna on Wednesday, where they are drafting the text of a final accord over Tehran's nuclear program before the June 30 deadline.

France said on Wednesday it would block a final deal unless Tehran allowed inspectors to access all of its installations, including military sites, which Iran's supreme leader, Ayatollah Ali Khamenei, explicitly ruled out last week, reports Reuters.

Both France and Iran said the deadline might have to be extended in order to work out technical details, which may appease Netanyahu, who has expressed concern that negotiators are rushing the process.

"As we are meeting, the P5+1 talks are reconvening, and I'm afraid they're rushing to what I consider is a very bad deal," Netanyahu told Cassidy, according to Netanyahu's office.

"I see no reason to rush to a deal and certainly not a bad deal that paves Iran's path to the bomb, but also fills Iran's coffers with tens of billions of dollars to pursue its aggression throughout the Middle East and around Israel's borders," he said, adding that he thinks "it's important to apply pressure to get a better deal" that avoids these pitfalls, reported CBN News.

"We shouldn't give Iran a path to nuclear weapons and billions of dollars to pursue aggression because of ISIS," Netanyahu concluded. "ISIS should be fought; Iran should be stopped."