Ukrainian president Petro Poroshenko said the restrictions have been imposed to prevent Russians from forming “private armies” in his country.
Moscow has been supporting Russian separatists in the east of the country with troops and weapons.
Poroshenko said: “There is no red line for Putin and this is the very strong reason why we should be together, the whole civilised world.
“Not only the leaders, with whom a very reliable partnership, but the people of UK, of Europe, USA, Canada, Australia, Japan, the whole civilised world would be together and this is very important for global security.”
Martial law has been imposed in the former Soviet state amid fears of attack, with the president saying he believes Putin wants to annex Ukraine.
Read more at Sky News.