The Prime Minister of the United Kingdom Boris Johnson has expressed concern over the increase in Russia’s military presence on the Ukrainian border and in the Russian-occupied Crimea.

He wrote about this on Twitter following a conversation with Ukrainian President Volodymyr Zelensky.

“I spoke with President Zelensky tonight about our concern about the destabilizing Russian military activity on Ukraine’s border. I reiterated Britain’s unwavering support for Ukraine’s sovereignty and territorial integrity,” Johnson wrote.

In addition, the British Prime Minister added that Britain will work to ensure that “there is no further escalation.” In turn, Ukrainian President Volodymyr Zelensky thanked Johnson for his “unwavering support” and called on Britain and other member states to strengthen their presence in the region and increase sanctions on Russia.