The Nour satellite placed into orbit on April 22 is classified by the US military as a small 3U Cubesat, three adjoined units each no more than a liter in volume and less than 1.3 kilograms (one pound) each, said General Jay Raymond in a tweet late Sunday.

"Iran states it has imaging capabilities -- actually, it's a tumbling webcam in space; unlikely providing intel," he wrote.

"#spaceishard," Raymond added to the tweet.

While Raymond downplayed any threat from the satellite, the United States has warned that Tehran's ability to place it into space represents a significant advance in its long-range missile capability, posing a greater threat to US forces and allies in the Middle East.

Last week US Secretary of State Mike Pompeo accused Iran of violating a 2015 UN Security Council resolution against Tehran advancing any nuclear-capable ballistic missile activities.

On Saturday, Pompeo called for the United Nations to extend its conventional arms embargo on Iran beyond its scheduled end in October.

"All peace-loving nations must reject Iran's development of ballistic-missile-capable technologies and join together to constrain Iran's dangerous missile programs," he said.