The U.S. Senate overwhelmingly endorsed language that sets a red line for Iran "nuclear capability."
The non-binding resolution, introduced in February by Sens. Bob Casey (D-Pa.), Lindsey Graham (R-S.C.) and Joseph Lieberman (I-Conn.) says that "it is a vital national interest of the United States to prevent the Government of Iran from acquiring a nuclear weapons capability."
The resolution passed late on Sept 21 by a vote of 90-1, with only Sen. Rand Paul (R-Ky.) voting against.
The language is in line with Israel's red lines, and goes farther than the Obama administration, which has set as a red line Iran's acquisition of a nuclear weapon.
It is not precisely clear what "capability" entails; a number of experts believe Iran has already crossed that threshold and is capable of manufacturing a nuclear weapon. Iran insists its nuclear program is strictly peaceful.
The American Israel Public Affairs Committee praised the resolution's passage. "AIPAC applauds the Senate for rejecting a policy of containment of an Iranian nuclear weapons capability and calling for an increase in sanctions against the world’s leading state sponsor of terror," the group said in a statement.
The U.S. House of Representatives passed similar language in May and the term "capability" has made it into other legislation, including the most recent sanctions legislation.