On 21st May, UNIAN in Ukraine reported that MMZ Avangard, supplier of the S-300 and S-400 surface-to-air missile (SAM) systems, the Gatchina SAM Training Centre and the Instrument Design Bureau (KBP) Tula had been made subject to US sanctions. The sanctions imposed by the State Department include a ban on export licences and on any business involving the US Government. A number of other concerns in China, Iran and Syria are also listed, together with a Chinese individual.
https://s3.amazonaws.com/public-inspection.federalregister.gov/2019-10664.pdf