AP -- The Senate is moving ahead on legislation that would renew a decades-old law that allows the United States to slap companies with economic sanctions for doing business with Iran.

A vote is scheduled Thursday on a 10-year extension of the Iran Sanctions Act. The bill's backers say extending the law allows the U.S. to punish Tehran should the country fail to live up to the terms of the landmark nuclear deal.

If the Senate approves the House-passed bill, it will be sent to President Barack Obama, and he is expected to sign it into law. The House last month voted overwhelmingly, 419-1, to approve the extension. The act, first passed by Congress in 1996 and renewed several times since then, expires at the end of the year.

The White House had previously laid out a litmus test for the renewal, saying Obama wouldn't sign it if it would undermine the nuclear accord. In exchange for Tehran rolling back its nuclear program, the U.S. and other world powers agreed to suspend wide-ranging oil and trade sanctions that had choked the Iranian economy.

But a senior Obama administration official said the sanctions renewal bill heading toward passage doesn't violate the terms of the nuclear deal, which clears the way for Obama to sign it should the Senate pass it. Still, the Obama administration considers the renewal unnecessary given the president's other authorities to sanction Iran, said the official, who wasn't authorized to comment publicly and spoke on condition of anonymity.

But congressional Republicans and Democrats view the law as valuable leverage. Senate Majority Leader Mitch McConnell said Thursday that preserving the sanctions is critical to blunt Iran's "persistent efforts to expand its sphere of influence" throughout the Middle East. He also criticized the administration for allowing itself to be "held hostage" by Iran's threats to withdraw from the nuclear agreement.

Sen. Ben Cardin of Maryland, the senior Democrat on the Senate Foreign Relations Committee, has said renewing the law is necessary if the U.S. wants to retain "a credible deterrent" of snapping sanctions back into place should Iran cheat on its obligations under the nuclear deal.

Congress approved the Iran Sanctions Act 20 years ago to block major foreign investment in Iran's energy sector. The goal was to deny Tehran the ability to financially support terrorism and build nuclear and ballistic missile capabilities.