Iran under the terms of a November 2013 agreement secured relief from some of the sanctions targeting its energy sector in exchange for a pledge to cut back on its nuclear research activity.
The International Atomic Energy Agency, the United Nations' nuclear watchdog, said Iran has converted its uranium stockpiles into a form that's difficult for use in a nuclear weapon.
The Treasury Department said members of the P5-plus-1 -- Britain, China, France, Russia, the United States plus Germany -- agreed with Iran to continue moving forward under the terms of the November 2013 joint plan of action.
"The U.S. government has extended through Nov. 24, 2014, the sanctions relief provided for in the joint plan of action," the Treasury Department said Monday.
Iran is limited to exporting approximately 1 million barrels of oil per day under the terms of the arrangement.
"We feel comfortable that the crude oil exports of Iran are remaining in the million to 1.1 million barrel a day average," she said.