DUBAI, United Arab Emirates (AP) — Iran appears to have attempted a second satellite launch despite U.S. criticism that its space program helps it develop ballistic missiles, satellite images released Thursday suggest. Iran has not acknowledged conducting such a launch.

Images released by the Colorado-based company DigitalGlobe show a rocket at the Imam Khomeini Space Center in Iran's Semnan province on Tuesday. Images from Wednesday show the rocket was gone with what appears to be burn marks on its launch pad.

Iranian state media did not immediately report on the rocket launch, though such delays have happened in previous launches.

Iran has said it would launch its Doosti, or "Friendship," satellite. A launch in January failed to put another satellite, Payam or "Message," into orbit.

The U.S. alleges such launches defy a U.N. Security Council resolution calling on Iran to undertake no activity related to ballistic missiles capable of delivering nuclear weapons.

Iran, which long has said it does not seek nuclear weapons, maintains its satellite launches and rocket tests do not have a military component. Tehran also says they don't violate a United Nations resolution that only "called upon" it not to conduct such tests.

Over the past decade, Iran has sent several short-lived satellites into orbit and in 2013 launched a monkey into space.

Iran usually displays space achievements in February during the anniversary of its 1979 Islamic Revolution. This year will mark the 40th anniversary of the revolution amid Iran facing increasing pressure from the U.S. under the administration of President Donald Trump.