Witkoff Warns GOP Senators of Mass Casualties if Israel Strikes Iran

White House envoy Steve Witkoff gave a private warning to top Senate Republicans last week, cautioning that if Israel attacks Iran’s nuclear facilities, the Iranian response could result in mass casualties, Axios reported Thursday. This was according to a U.S. official and a source with direct knowledge of the meeting.

As Israel prepares to potentially strike Iran quickly if diplomacy falls apart over the weekend, Witkoff issued stark warnings about the consequences. He said that Iran’s retaliation could severely strain Israel’s defensive systems and lead to devastating destruction.

Iran has also threatened to retaliate against U.S. targets in the region if its nuclear infrastructure is attacked. In anticipation of this, the U.S. is currently withdrawing diplomats and military families from vulnerable locations.

President Trump told reporters on Thursday that while he wouldn’t confirm an Israeli strike is “imminent,” he acknowledged “it might very well happen.” Trump emphasized his desire to prevent a conflict, but said Iran would need to make concessions, something they have so far refused to do.

Witkoff is scheduled to enter a sixth round of nuclear negotiations with Iran on Sunday, a meeting that could mark the end of the diplomatic track.

According to Israeli officials, the IDF is on heightened alert. Prime Minister Binyamin Netanyahu is reportedly waiting for President Trump’s final approval before taking any military action.

Behind closed doors last Thursday, Witkoff held a classified briefing on Iran with several Republican senators, including Sens. Risch, Graham, Barasso, and Ricketts, according to a source familiar with the meeting.

Witkoff told the senators that Israeli military action remains an option if no diplomatic deal is reached. He highlighted Iran’s ballistic missile capabilities as a major concern. U.S. officials fear Israel’s missile defense systems could be overwhelmed by a large-scale Iranian attack.

Such a strike, he warned, could result in massive loss of life and widespread devastation.

Witkoff repeated these concerns during a speech in New York on Wednesday, describing Iran’s missile program as “as big of an existential threat” to Israel as its nuclear ambitions.

A U.S. official said intelligence estimates show Iran possesses around 2,000 ballistic missiles, some capable of delivering over 2,000 pounds of explosives. Many of these missiles can easily reach Israeli territory.

On Wednesday, Iran’s defense minister claimed the country had developed a new missile with a 4,000-pound warhead.

According to the U.S. official, Iran has sharply ramped up missile production since its last strike on Israel in October 2024, now producing approximately 50 missiles per month.

Iran’s apparent strategy, the official said, is to produce more ballistic missiles than Israel has interceptors to defend against them.

CENTCOM commander Gen. Erik Kurilla is expected to arrive in Israel on Saturday for high-level talks with political and military leaders about Iran, according to Israeli officials. He will also visit other countries in the region.

Kurilla testified before the House Armed Services Committee on Tuesday that a potential Israeli strike on Iran could put U.S. forces across the Middle East in danger of Iranian retaliation.

In response to the rising threat level, the U.S. is evacuating non-essential staff from its Baghdad embassy and removing family members of troops stationed at several Gulf bases. On Thursday, the State Department imposed new security restrictions on American diplomats and their families in Israel.

Iran’s President Masoud Pezeshkian declared on Thursday that his country will not halt uranium enrichment, rejecting Trump’s demands.

“If they destroy our (nuclear facilities) with a bomb, they will be destroyed. All these capabilities are in our minds, and therefore, whatever they do, we will rebuild,” Pezeshkian said.

Gen. Hossein Salami, commander of Iran’s Islamic Revolutionary Guard Corps, also said on Thursday that Iran is prepared for war and has already selected its targets.

He warned that any Israeli attack would trigger a response “more painful and more destructive” than the two major missile barrages Iran launched against Israel last year.

Iran also announced new military exercises on Thursday, which it said would be focused on monitoring “enemy movements.”

Despite the threat, Israeli officials have expressed confidence that they can withstand a repeat of the previous missile attacks, which caused relatively limited damage and casualties.

Witkoff is scheduled to meet Iranian Foreign Minister Abbas Araghchi in Oman on Sunday to hear Tehran’s response to the latest U.S. nuclear deal proposal.

That meeting may decide whether diplomacy continues or gives way to military action.

Israel’s security cabinet is expected to convene on Thursday to assess the worsening crisis.

Witkoff spoke with Netanyahu on Wednesday to address the escalating tensions, and is set to meet with his senior adviser Ron Dermer and Mossad director David Barnea on Friday before traveling to Oman, an Israeli official said.

Araghchi warned that a resolution passed Thursday by the International Atomic Energy Agency condemning Iran could further complicate negotiations.

In response, Iran has pledged to escalate specific nuclear activities.

Israel is now preparing to launch a rapid strike on Iran’s nuclear sites if the talks break down, according to two Israeli sources familiar with internal discussions.

Israeli intelligence recently shifted its assessment—moving from the belief that a nuclear deal was near, to the view that negotiations could collapse soon.

Israel has assured the White House that it won’t act without a clear signal from Trump that the talks have failed, according to two officials with direct knowledge of the matter.

This assurance is significant because U.S. officials have grown increasingly concerned that Israel might strike Iran even while negotiations are still ongoing. Trump has cautioned Netanyahu against making a move prematurely.

On Thursday, Iran warned that it may transfer its nuclear materials to secret, undeclared sites to shield them from a potential Israeli strike.

This threat was made in a formal letter sent by Foreign Minister Araghchi to both the UN secretary-general and the head of the International Atomic Energy Agency, signaling a serious escalation in the already high-stakes standoff.