Ukrainian President Volodymyr Zelensky is scheduled to meet French President Emmanuel Macron and German Chancellor Angela Merkel on Friday for talks over the escalating tensions in eastern Ukraine.

Tensions have built up between insurgents in Donbass and Ukrainian government forces this year and Russian President Vladimir Putin's deputy chief of staff said Russia will be forced to protect the residents of Donbass if Ukraine launches full-scale hostilities against the region.

Defense Minister Sergei Shoigu said Moscow had moved two armies and three paratrooper units to its western border as part of a large snap drill meant to test combat readiness and respond to what he called threatening military action by NATO.

In response, Ukraine's armed forces on Wednesday rehearsed repelling a tank and infantry attack near the border of Russia-annexed Crimea.

While Zelensky and Macron will meet physically in Paris on Friday, Merkel will join in the talks via videoconference.

The talks are also expected to focus on the state of Ukrainian reforms, in particular, the creation of an independent and reliable judiciary.

(With input from agencies)