Obama will sign Iran sanctions bill passed by Senate
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The Senate easily passed an extension of an Iran sanctions law on Thursday, sending the legislation to President Obama’s desk.

Senators voted 99-0 to approve a 10-year extension of the Iran Sanctions Act, which includes penalties against Iran’s banking, defense and energy sectors. The law was set to expire at the end of the year.

Sen. Bernie SandersBernard (Bernie) SandersDems ponder gender politics of 2020 nominee 2020 Dem contenders travel to key primary states After Florida school shooting, vows for change but no clear path forward MORE (I-Vt.) didn't vote.

Obama is expected to sign the legislation, a White House official said Thursday, ending weeks of uncertainty about a possible veto. 

The official said the administration has determined the measure does not violate the Iran nuclear agreement, meeting a condition had Obama set to earn his signature. 

Lawmakers argue the sanctions extension is needed as a failsafe in case Iran breaks its commitment under the landmark pact reached last year. 

Under the deal, Iran agreed to curtail its nuclear program in exchange for the United States and other countries lifting economic sanctions.

"The practical effect is the Iran nuclear agreement depends on our resolve, on our commitment to... stop a nuclear-armed Iran by using sanctions and other means if necessary," said Sen. Richard Blumenthal (D-Conn.), who supported the Iran deal.

Even though Obama will sign the measure into law, the White House said it views it as unnecessary, arguing the administration has broad latitude to punish Iran if it violates its commitments to the deal. 

Senate Republicans, including Foreign Relations Committee Chairman Bob CorkerRobert (Bob) Phillips CorkerCongress punts fight over Dreamers to March Drama surrounding Shulkin — what is the future of VA health care? Blackburn pushes back on potential Corker bid: 'I'm going to win' MORE (R-Tenn.), initially wanted to pass the extension as part of a broader bill that would also bolster sanctions against Iran for a string of ballistic missile tests.

But Democrats signaled early that they wouldn't support anything besides a "clean" extension of the law.

Senate Majority Leader Mitch McConnellAddison (Mitch) Mitchell McConnellLawmakers feel pressure on guns Bipartisan group of House lawmakers urge action on Export-Import Bank nominees Curbelo Dem rival lashes out over immigration failure MORE (R-Ky.) indicated Thursday the extension would give President-Elect Donald TrumpDonald John TrumpAccuser says Trump should be afraid of the truth Woman behind pro-Trump Facebook page denies being influenced by Russians Shulkin says he has White House approval to root out 'subversion' at VA MORE and a GOP-controlled Congress flexibility as they review Obama's Iran policies next year. 

“These authorities should remain in place as we address how best to deal with Iranian missile tests, support to Hezbollah and the Syrian regime," he said.

The extension easily passed the House last week in a 419-1 vote, but Obama had faced external pressure to reject the legislation.

Ayatollah Ali Khamenei, Iran's supreme leader, warned last week that extending the sanctions law would constitute a violation of the nuclear deal.

"The most recent of them is the 10-year extension of the sanctions. If these sanctions are extended, it will surely constitute a violation of the [Joint Comprehensive Plan of Action] and they should know that the Islamic Republic will definitely react to it,” he said. 

Jordan Fabian contributed. This story was updated at 3:07 p.m.