The European Commission condemned as "barbaric" Russian missile strikes on Kyiv and other Ukrainian cities on Monday and warned Belarus against helping its ally kill civilians.
EU foreign policy chief Josep Borrell said Russia's acts had "no place in the 21st century", adding in a tweet that military support for Ukraine from the bloc was on its way.
Russia pounded cities across Ukraine during rush hour in apparent revenge strikes after President Vladimir Putin declared a blast on Russia's bridge to Crimea to be a terrorist attack.
"They are barbaric and cowardly attacks... targeting innocent civilians on their way to work and school in the morning traffic," Peter Stano, a spokesperson for the European Union's executive arm told the Commission's daily news briefing.
He described the strikes as a contravention of international humanitarian law and said Russia's political and military leadership would be held accountable for these and other war crimes.
The Commission urged Belarus to refrain from any involvement in Russia's "brutal illegitimate undertaking" that violated the United Nations Charter and international law.
Specifically, it told Minsk immediately to stop allowing the territory of Belarus to serve as a launch pad for very recent missile strikes and drone attacks against Ukrainian civilians.
"Any further actions and in particular the Belarusian military’s direct involvement into this war, against the will of the vast majority of the Belarusian people, will be met by new and strong restrictive measures," Stano said.
Belarusian President Alexander Lukashenko said on Monday he had ordered troops to deploy with Russian forces near Ukraine in response to what he said was a clear threat to Belarus from Kyiv and its backers in the West.
(Reporting by Charlotte Van Campenhout and Philip Blenkinsop; Editing by John Chalmers and Tomasz Janowski)
