The UK on Tuesday slapped new sanctions on 25 companies and individuals to "close the net" on Russian President Vladimir Putin's access to foreign military equipment.
Those targeted include people and businesses in Turkey, Dubai, Slovakia and Switzerland that the Foreign Office said are "supporting the illegal war in Ukraine".
Sanctions have also been imposed on Iranians involved in producing drones for the Islamic Revolutionary Guard Corps (IRGC) and Belarusian defence organisations linked to the manufacturing of military technology for the Belarusian regime.
"Today's landmark sanctions will further diminish Russia's arsenal and close the net on supply chains propping up Putin's now struggling defence industry," Foreign Secretary James Cleverly said.
"There is nowhere for those sustaining Russia's military machine to hide."
Three Russian companies operating in the electronics sector are among those targeted, with the other 22 new sanctions involving entities and individuals outside the country.
They include two Turkey-based businesses said to be exporting microelectronics to Russia's military and a Dubai-based supplier of drone components.
It comes as part of a wider sanctions package targeting those that the UK deems "critical to supplying and funding Putin's war machine" and is the biggest ever UK action on military suppliers in third countries.
