EU's Tusk Condemns 'Russia's Aggression' after Ukraine Deaths

EU President Donald Tusk fired off an angry broadside at the Kremlin Friday, urging European vigilance and condemning "Russia's aggression" in Ukraine after five soldiers were killed there.

The spike in fighting coincided with a summit in Brussels between the EU and six former Soviet countries, where the war between Kiev government forces and Russian-backed separatists was conspicuously absent from the official agenda.

"The death of five Ukrainian servicemen... is just the latest proof of the tragic consequence of Russia's aggression in Ukraine," Tusk told a news conference.

Tusk, who grew up in Soviet-dominated communist Poland, said he "would not hesitate to choose" between the Russian and Western worldviews.

"One of the biggest threats today is the real threat when it comes to cyber attacks, fake news, hybrid war," he said.

He pointed to a recent speech by British Prime Minister Theresa May which he said was "about hostile activities during the British referendum for example."

In the speech, May in fact made no direct reference to the Brexit referendum to leave the EU, but did condemn Russia's "sustained campaign of cyber espionage and disruption", including meddling in European elections.

"We also remember some very brutal events during the elections in some member states in the EU but also in the United States," Tusk, a former Polish prime minister, said.

"This is why we have to be very, very cautious, vigilant and also honest -- if you want to protect ourselves, if you want to help our partners from Eastern Partnership, we have to first of all be aware of threats inside the EU."

Tusk's remarks come after he questioned on Sunday whether recent tensions between the rightwing government in Warsaw and Ukraine and the EU were part of a "Kremlin plan."