Israeli Prime Minister Benjamin Netanyahu repeated his warning about a possible nuclear deal with Iran on Wednesday, saying the world must insist on a "better deal" that links concessions to a change in Tehran's behavior.

As negotiators continued talks in Switzerland a day after abandoning a March 31 deadline to reach the outline of a nuclear deal, Netanyahu said world powers were looking to ease sanctions on Iran while it continued to wreak havoc in the Middle East and threaten Israel with annihilation. He says a weak deal will endanger not only Israel but other nations.

Netanyahu said Iran views Israel's destruction as non-negotiable, "but evidently giving Iran's murderous regime a clear path to the bomb is negotiable. This is unconscionable," he said. "At the same time, Iran is accelerating its campaign of terror, subjugation and conquest throughout the region, most recently in Yemen."

Netanyahu said a better deal would "significantly roll back Iran's nuclear infrastructure" and link a lifting of restrictions on its nuclear program to "a change in Iran's behavior."

Netanyahu has been a fierce critic of Western efforts to reach a deal with Iran. While Iran insists its program is for peaceful purposes, Israel and Western nations suspect it is seeking a weapons capability. Netanyahu says no deal should allow Iran to continue enriching uranium and has raised several other reservations about the emerging deal.

The discussions dragged on in Lausanne, Switzerland, even as a self-imposed deadline passed and three of the six foreign ministers involved left the talks.

Claiming enough progress had been made to warrant an extension after six days of intense negotiations and eager to avoid a collapse in the discussions, U.S. Secretary of State John Kerry and his British and German counterparts huddled with Iranian Foreign Minister Mohammed Javad Zarif in a marathon effort to bridge still significant gaps and hammer out details of a framework accord. The foreign ministers of China, France and Russia all departed overnight with no deal reached.