The plans include a mix of airstrikes and commando operations that vary in severity and could set back Tehran's ability to weaponize its nuclear program by just months or a year or more, sources said.

Mr. Trump’s chief envoy to the talks, Steve Witkoff, has also sent mixed signals over what the United States wants. Over the past week, he has moved from suggesting Iran could have a limited nuclear program to saying Iran needed to fully dismantle it.

The United States and Iran are due to hold their second round of nuclear talks on Saturday, as what both sides are looking for in a deal begins to take shape.