The US Senate unanimously voted to extend the Iran Sanctions Act (ISA) by ten years on Thursday.

The bill was passed by a vote of 99-0. It had previously been approved by a vote of 419-1 in the House of Representatives. President Barack Obama still has to sign the bill for it to become law.

The Obama Administration had hinted that it would have preferred not to sign the bill into law. It was passed with a veto-proof majority, however.

The ISA, which was first passed in 1996, enacts sanctions on companies that invest in Iran's energy sector in order to deter the Islamic Republic's pursuit of nuclear weapons.

Iranian Supreme Leader Ayatollah Ali Khamenei has threatened "revenge" against the US if the ISA extension is passed. He said that Iran would "retaliate" and that it would consider such a move to be a violation of the nuclear deal Iran signed with Western powers in 2015.

Senate Majority Leader Mitch McConnell said that the law is meant to enable the US to stop Iran’s “persistent efforts to expand its sphere of influence.” Senator Ben Cardin, the senior Democrat on the Senate Foreign Relations Committee, said that renewing the ISA was necessary to create a “credible deterrent” should Iran violate the nuclear deal.