Ukraine raises a flag on a symbolic island

STORY: In a sign of defiance against Moscow, a Ukrainian flag is raised on a recaptured Black Sea island.

This video of soldiers installing the flag was released Thursday by Ukraine's Armed Forces.

Reuters was able to verify the location through satellite images.

The strategic Snake Island has been a point of contention in the war, captured by Moscow in February.

It had become a symbol of Ukraine's refusal to bend to Russia.

Russian forces withdrew from there at the end of June in what it called a gesture of goodwill.

But it was quick to respond to the flag-raising ceremony. With Russia's defense ministry claiming warplanes struck the island shortly after, killing an unspecified number of Ukrainian troops.

Meanwhile, Kyiv has lost a major ally in British Prime Minister Boris Johnson, who announced he will be stepping down.

Moscow has long criticized Johnson for arming Kyiv and openly celebrated his downfall on Thursday.

It comes as Russian forces keep up pressure in Eastern Ukraine.

After cementing control of the Luhansk region, Moscow has made clear it's planning to capture parts of neighboring Donetsk, which it has not yet seized.