Ukrainian Defence Minister Oleksii Reznikov said on Wednesday the country is set to face “extremely difficult weeks” of heavy fighting ahead due to the large-scale offensive Russia is preparing to launch on the eastern Donbas region.

“We have several extremely difficult weeks ahead of us. The implementation of agreements [with Ukraine’s international partners], training [of military personnel], and logistics all take time. Meanwhile, Russia has already gathered strength for a large-scale offensive in eastern Ukraine,” the Pravda news portal cited Reznikov as saying.

The defense minister added: “The enemy is already aware of its strategic defeat but will still try to inflict as much pain on us as possible. Unfortunately, we will lose more of our soldiers before the victory. There will be more destruction and painful losses.”

Russia said on Friday it plans to take full control of the Donbas and southern Ukraine during the second phase of what it calls its “special military operation”.

Russian President Vladimir Putin’s claimed last week to have seized full control of the besieged port city of Mariupol and ordered the blockade of the Azovstal steel plant, the main remaining Ukrainian stronghold in Mariupol in Donbas.

Mariupol has been under relentless bombardment for weeks. It is a strategic target for the Russians that would allow Moscow to establish control over territory linking the Donbas in south-eastern Ukraine to annexed Crimea.