UK Defence Intelligence has analysed the advance of Russian forces in Donetsk Oblast, specifically on the Pokrovsk front.
Russia is believed to be storing Oreshnik missiles in Belarus with the potential to reach European capitals in minutes.
As the war in Ukraine rages, Germany and the Baltic states have warned Vladimir Putin's aggression could spread in Europe.
The UK is considering participating in a €1.5 billion ($1.6 billion) fund being set up by the European Union to bolster the regional defense industry, people familiar with the matter said.