The US announced Monday it is sanctioning a wide swathe of Iran's defense industry, including its ministry, in a bid to prevent the country from trading in arms ahead of the looming expiration of a UN embargo.

Addressing reporters at the State Department, Secretary of State Mike Pompeo said the sanctions target Iran's defense ministry and its Defense Industries Organization, which is a conglomerate of companies that support the defense ministry, as well as its director.

Venezuelan President Nicolas Maduro is the first individual to face follow-on sanctions, Pompeo announced, casting the penalty as a warning to all other nations against trading in arms with Iran.

"For nearly two years corrupt officials in Tehran have worked with the illegitimate regime in Venezuela to flout the UN arms embargo," the top diplomat said. "Our actions today are a warning that should be heard worldwide: No matter who you are, if you violate the UN arms embargo on Iran you risk sanctions.”

The US has unilaterally announced it will enforce all UN sanctions on Iran that were lifted or eased as part of the 2015 nuclear agreement Tehran struck with world powers. The agreement placed unprecedented curbs on the country's nuclear program in exchange for relief from the biting economic penalties.

Under the agreement the UN's arms embargo on Iran is due to expire in October after the US failed to pass a Security Council resolution that would have extended it further.

The US move to re-enforce UN sanctions on Iran in a process known as "snapback" is also intended to ensure the embargo doesn't lapse, but none of the nuclear deal's other signatories agree the US has standing to invoke the mechanism after US President Donald Trump unilaterally left the Joint Comprehensive Plan of Action in 2018.