Belarus

The announcement came after two days of failed ceasefires to let civilians escape the besieged city of Mariupol, where hundreds of thousands of people are trapped without food and water, under relentless bombardment and unable to evacuate their wounded.

The new "corridors" would be opened at 10 am Moscow time (8pm NZT) from the capital Kyiv and the eastern cities of Kharkiv and Sumy, as well as Mariupol, Russia's defence ministry said.

Thousands of people are at the border with Poland, enduring freezing conditions in the hope of crossing into the European Union.

EU officials have accused Belarus of provoking the crisis to undermine its security, an allegation it denies.

In retaliation, the EU is reportedly planning a fresh package of sanctions.

But on Thursday the country's long-time authoritarian leader Alexander Lukashenko warned: "If they impose additional sanctions on us... we must respond."

This is after banning the Belarusian ministry of sport official who smuggled a Russian flag into Wednesday night’s opening ceremony at the Maracanã.