As diplomats discuss a long-term agreement on Iran's nuclear program, a majority of senators Tuesday increased pressure on President Obama to make sure he includes key provisions.
In a letter to the president, 83 senators outlined "core principles" they believe must be in a final agreement. Negotiations among Russia, China, Germany, France, the United Kingdom, the United States, and Iran are ongoing in Vienna.
At the top of their list is an assertion that the final agreement must underline that Iran has no right to uranium enrichment under the Nuclear Non-Proliferation Treaty. It's a long-contested subject, and an idea that Iranian officials have rejected.
Senators are pressing for a handful of other provisions as part of a long-term deal, including:
A dismantling of Iran's nuclear-weapons program.
The shuttering of Iran's heavy-water reactor at Arak, explanations on "questionable activities" at other reactors, and stressing that Iran "has no reason" to have an underground enrichment facility.
The tackling of previous concerns raised by the United Nation's Security Council, including questions about whether the program has a military aspect. International Atomic Energy Agency officials have expressed hope that they can get to the bottom of a long-standing investigation over any military-related programs.
Iran must allow "long-term and intrusive inspection and verification" at its sites to make sure it cannot try to get or build a nuclear weapon.
And the senators are giving the administration a reason to pay attention to its request: sanctions. They note that if the president wants a long-term rollback of sanctions "beyond existing waiver authority" as part of an "acceptable" final agreement on Iran's nuclear program, it will have to work with Congress
Many of the senators have backed long-stalled legislation to increase sanctions against Iran if it violates the interim agreement reached last year or walks away from talks over a long-term deal. The Obama administration and Iranian officials have stressed that any sanctions legislation would kill diplomatic progress.
But the bipartisan group contends "that the pressure from economic sanctions brought Iran to the table, and that it must continue until Iran abandons its efforts to build a nuclear weapon."