The UK will sanction 178 individuals, targeting those supporting Russian-backed separatists in eastern Ukraine, the Foreign Office announced on Wednesday.
The sanctions are being coordinated with the European Union.
The Russia-Ukraine war has drawn international outrage, with the European Union, US and UK, among others, implementing tough financial sanctions on Moscow.
At least 1,892 civilians have been killed and 2,558 injured in Ukraine since Russia started the war on its neighbor on Feb. 24, according to UN estimates, with the true figure believed to be much higher.
More than 4.24 million Ukrainians have fled to other countries, with millions more internally displaced, according to the UN refugee agency.