WASHINGTON (REUTERS) - The United States imposed sanctions on Iran's civilian space agency and two research organisations on Tuesday (Sept 3), saying they were being used to advance Teheran's ballistic missile program.

The US Treasury sanctions targeted the Iran Space Agency, Iran Space Research Centre and the Astronautics Research Institute, according to a statement on its website.

"The United States will not allow Iran to use its space launch programme as cover to advance its ballistic missile programmes," Secretary of State Mike Pompeo said in a statement.

He said Iran's Aug 29 attempt to test a space launch vehicle underscored "the urgency of the threat."

The United States has warned Iran against rocket launches, fearing the technology used to put satellites in orbit could help it develop the ballistic missile capability needed to launch nuclear warheads.

Teheran denies its activity is a cover for such development.

On Friday, US President Donald Trump posted on Twitter a photo of what appeared to be the site of a failed Iranian satellite launch.

"These designations should serve as a warning to the international scientific community that collaborating with Iran's space programme could contribute to Teheran's ability to develop a nuclear weapon delivery system," Pompeo said.

Trump withdrew from a 2015 multi-national nuclear deal with Iran, saying it did not go far enough.