Rep. Michael Waltz of Florida, who served in the Middle East as one of the Army's elite Green Berets, told DailyMail.com their leave at a critical point in the discussions shows how President Joe Biden's policies are putting the "national security at risk."
A State Department official assured that Richard Nephew, the architect of sanctions on Tehran, had left as U.S. Deputy Special Envoy for Iran after demanding a stricter view on nuclear talks.
At the same time, the Wall Street Journal reported that two other negotiators had stepped aside from their positions because they wanted a more challenging negotiating stance.
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Waltz joined their call on Tuesday by prompting Biden to return to his predecessor Donald Trump's "policy of maximum pressure" against Iran's regime.
"It's good to see some officials recognize when diplomacy gets too desperate and begins to really put American national security at risk," the Florida Republican said.
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"The Biden Administration should revert back to a policy of maximum pressure that focused on holding the Iran regime accountable for their nuclear capabilities, missile development, and regional terrorism and build on Abraham Accords to counter Iran's aggression."
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The discussing team's policy differences reportedly involved the enforcement of existing sanctions and even pulling out of the talks entirely.
Their leave was another blow to President Joe Biden's foreign policy goals and a State Department conflict with Russian diplomats who appear poised for war in Ukraine, coming at a critical time in negotiations that resumed two months ago.
Western diplomats say they hope for a breakthrough in the coming weeks, but critical differences remain between the two sides, and Britain warned of imminent trouble on Tuesday.
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Meanwhile, the Biden Administration has been facing bipartisan criticism at home that it's conducted an overly soft stance against Iran as the Middle Eastern nation builds up its nuclear capabilities at breakneck speed.
A State Department official declined to comment on the specifics of internal policy discussions.
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"The previous Administration left us with a terrible set of choices on Iran," he said.
"Maximum pressure failed, leaving Iran with a rapidly expanding nuclear program and a more aggressive regional posture. At the same time, we were isolated from many of our closest allies and partners.
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"Working our way out of this crisis requires many difficult, closely balanced decisions, on which there can be reasonable disagreement." Nephew, who wanted Biden to take a more rigid stance against Iran, has reportedly been avoiding the meetings in Vienna since December.
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