In excerpts of an interview with the German daily Frankfurter Allgemeine Zeitung published in advance, he called for sanctions on the Tehran regime to be stepped up rather than eased.
"A bad deal is worse than no deal," the prime minister was quoted as saying.
Iran "will ask for a partial lifting of sanctions for cosmetic concessions that would leave them with the ability to have a nuclear weapons capability," Netanyahu was quoted as saying.
"You demand enrichment if you want to build nuclear weapons," he stressed.
Global powers accuse Iran of seeking to obtain a nuclear bomb under the guise of what Tehran insists is its civilian atomic energy programme.
But recent US-Iranian talks have raised hopes of progress in Geneva on October 15-16 when Iran meets the United States, Russia, China, Britain, France and Germany.