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Debbie Hill, Pool, Associated Press
Israel's Prime Minister Benjamin Netanyahu makes statements during a press conference at the prime minister's office in Jerusalem, Wednesday, April 1, 2015.

JERUSALEM — Israeli Prime Minister Benjamin Netanyahu on Wednesday made a last-ditch appeal for world powers to call off an emerging nuclear agreement with Iran, saying the world must insist on a "better deal" that links concessions to a change in Tehran's behavior.

His remarks came as U.S. House Speaker John Boehner, R-Ohio, arrived as part of a regional visit. U.S. Republicans share Netanyahu's concerns and have pushed for tougher sanctions on Iran, which the White House says would scuttle the talks. Last month, Boehner helped engineer a speech to Congress by Netanyahu, against the White House's wishes, in which the Israeli leader harshly criticized the possible nuclear deal.

As negotiators continued talks in Switzerland a day after abandoning a March 31 deadline to reach the outline of a 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 said a weak deal will reward Iran's intransigence and endanger not only Israel but other nations in the region.

In an English-language statement to international media, Netanyahu said that 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."

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."

"Iran must stop its aggression in the region, stop its terrorism throughout the world and stop its threats to annihilate Israel. That should be non-negotiable and that's the deal that the world powers must insist upon," he said.

Netanyahu has been a fierce critic of Western efforts to reach a deal with Iran and clashed openly with President Barack Obama over the wisdom of his outreach to the Islamic Republic.

While Iran insists its nuclear 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 says the emerging agreement would leave much of Iran's nuclear infrastructure in place. He has also pointed to Iran's development of long-range missiles and accuses Iran of backing radical Islamic forces across the region. Netanyahu has claimed that many Arab governments agree with him on the issue.

The Obama administration has made a nuclear deal with Iran its primary foreign policy focus, and the outcome of the high-stakes negotiations could largely define his presidential legacy.

In addition to Netanyahu and several Arab nations, he has also faced opposition from Republicans at home who are eager to press forward with new, stiffer sanctions on Iran.

Neither Boehner nor Netanyahu mentioned Iran during a joint appearance for the media, in what may have been an attempt to avoid further tensions with the White House. Netanyahu's speech to Congress last month, which was not coordinated with the White House in a breach of protocol, infuriated the Obama administration and worsened already strained ties between the Israeli and U.S. leaders.

"We've spent the last five days throughout the Middle East, and regardless of where in the Middle East we've been, the message has been the same: You can't continue to turn your eye away from the threats that face all of us," Boehner said in Jerusalem alongside Netanyahu.

The discussions meanwhile 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 gaps and hammer out details of a framework accord. The foreign ministers of China, France and Russia all departed overnight.