Iran's foreign minister said on Saturday that accusations about activity at its Parchin military site were "lies" spread by opponents of its landmark nuclear deal with world powers clinched last month.
A U.S. think-tank on Friday questioned Tehran's explanation that activity at its Parchin military site visible in satellite imagery was related to road work, and suggested it was a clean-up operation before IAEA inspectors arrive at the site.
"We said that the activities in Parchin are related to road construction," Foreign Minister Mohammad Javad Zarif was quoted as saying by the IRNA state news agency.
"They (opponents of the deal) have spread these lies before. Their goal is to damage the agreement," he added.
The Institute for Science and International Security in Wshington was quick to deny on Twitter that it was one of the deal's opponents.
"We are neutral," the thinktank said.
Parchin is a site to which the U.N. nuclear watchdog, the International Atomic Energy Agency (IAEA), requested access as part of the July 14 nuclear accord between Iran and six major powers, which include the United States.
Iran's parliament speaker was also dismissive of the think-tank's suggestion.
"This is an artificial dispute to distract the world," Ali Larijani was quoted on Saturday by the Fars news agency as saying. Larijani said Israel, unhappy with the deal, was trying to stop it from going ahead.
Israeli Prime Minister Benjamin Netanyahu has been pushing U.S. lawmakers to oppose the nuclear agreement, which he considers a threat to his country's survival.
Some pro-Israel groups have spent millions of dollars on an advertising campaign to persuade members of the U.S. Congress to reject the deal in the autumn.