Ukrainian troops are deserting battle and Russian troops have 'troubled' morale as the war is expected to last years, NATO chief says

Russian troops are facing troubles as the invasion of Ukraine could last for years, officials said.

The British defense ministry said that combat units from both sides are committed to intense combat in the Donbas.

The defense ministry said thatUkrainian forces have suffered desertions in recent weeks.

There have been cases of whole Russian units refusing orders and armed stand offs between officers and their troops.

NATO Secretary-General Jens Stoltenberg warned that nobody knew how long the war would last.

"We need to be prepared for it to last for a long time, even if the costs are high, not only in terms of military aid but also because of the increase in energy and food goods prices," said NATO Secretary General Jens Stoltenberg.

Russia warned Germany and France not to send arms to Ukraine in May, as Germany reduced its military support to the country.