A Japanese daily says North Korea is believed to be providing Iran with technicians to help develop nuclear arms and missiles.

The Mainichi Shimbun quoted a source in North Korea in its Monday edition that two-hundred North Korean technicians are providing their expertise at 12 different regions in Iran, including Natanz, which houses a uranium enrichment facility.

The paper said the North’s move apparently comes as Pyongyang is having difficulties in exporting weapons in the face of international sanctions that were imposed after the North conducted two nuclear tests.

The daily added that the United States is stepping up vigilance on the North in light of the likelihood that the communist nation is transferring military technologies to other countries.

Before the Iranian Revolution in 1979, Iran purchased weapons from the U.S. but such imports became illegal following the revolution. Iran then began to import missiles from the North in order to counter Scud missile attacks staged by Iraq during the Gulf War.