The U.S. federal government is "comfortable" with the amount of crude oil exported from Iran, a spokeswoman for the State Department said.

Iran secured consent to export around 1 million barrels of oil per day as part of a November agreement to curb its nuclear activity.

U.S. State Department spokeswoman Jen Psaki said Iran has been operating according to the terms of agreement.

"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 during her regular press briefing Thursday.

Iran this week brushed off reports from the International Energy Agency saying its crude oil exports were in decline.

IEA in its latest monthly market report suggested Iranian crude oil exports were down considerably.

Iran says fluctuations in export volumes are normal.

Psaki said Iran isn't skirting its international obligations, though Washington is monitoring the situation closely.

"The secretary [of state] maintains, [and] the president maintains, of course, the right to call for, embrace, endorse, advocate for any legislation if they so see fit in the future," she said.