Ukrainian President Volodymyr Zelenskyy warned that Russia's invasion of his country was just the beginning and that Moscow has designs on capturing other countries, after a Russian general said it wants full control over southern Ukraine.

"All the nations that, like us, believe in the victory of life over death must fight with us. They must help us, because we are the first in line. And who will come next?" Zelenskyy said in a video address late on Friday.

Rustam Minnekayev, deputy commander of Russia's central military district, was quoted by Russian state news agencies as saying full control over southern Ukraine would give it access to Transnistria, a breakaway Russian-occupied part of Moldova in the west.