"As we move forward with these negotiations, I want everyone to know that I am committed to getting this legislation to the floor sometime after we return in January," said Reid, a Democrat, as Congress adjourned for Christmas recess.
Unilateral US sanctions targeting Iranian financial and commercial activities are among the tools the United States has wielded in an effort to convince Tehran to abandon uranium enrichment.
Iran has so far rejected calls for it to limit its nuclear program, which many in the international community fear masks a weapons drive, but Tehran insists is intended to provide civilian nuclear energy.
Senator Christopher Dodd, chairman of the Senate Banking Committee and one of the main sponsors of the sanction legislation, praised Reid's commitment, adding: "My primary goal with this bill is to prevent Iran from developing a nuclear weapons capability."
The legislation, which includes sanctions that can be slapped on foreign companies with more than 20 million dollars of investments in Iran's energy sector, was approved by the Banking Committee at end of October.
Iran's top suppliers of refined petroleum are Swiss companies Vitol and Glencore, Dutch-Swiss Trafigura, France's Total, Britain's British Petroleum, and Indian company Reliance.
While Iran is a major producer of crude oil, it lacks the capacity to refine the product, forcing it to import 40 percent of its gasoline.
The House of Representatives approved its own legislation containing new sanctions on December 15.
Also Thursday, a spokesman for Senator John Kerry denied numerous US media reports that the former Democratic presidential nominee would visit Iran.
"Senator Kerry has no plans to travel to Iran," spokesman Frederick Jones told AFP.
