Vladimir Putin’s troops have been forced to regroup while suffering over 400 casualties a day in a drive to capture the eastern Ukrainian city of Avdiivka, Donetsk, Kyiv claimed. “The enemy is trying to move forward and then we beat them back,” Oleksandr Shtupun, a spokesperson for Ukraine‘s southern groups of forces, said. “So by no means can you speak of a fixed situation of some sort. Heavy fighting is continuing, though activity has subsided somewhat. The enemy is going through some kind of regrouping.” Mr Shtupun said Russian forces had suffered over 400 casualties a day in its campaign which has relied on small assault groups of 30 to 40 men. Meanwhile, North Korea has shipped over 1,000 containers of military equipment to Russia, according to the UK Ministry of Defence. It said Pyongyang was set to become one of Russia’s most significant foreign arms suppliers alongside Iran and Belarus. On Wednesday, Vladimir Putin tested Russia’s ability to launch a massive retaliatory nuclear strike as he pulled the country out of an international test ban treaty. Read More Moscow succession: What would happen if Putin dies? Russia is executing its own retreating soldiers as Ukraine offensive fails, says US A Russia without Putin? Be careful what you wish for... Putin’s many ‘heart attacks’ and why the rumours may be in his favour