Ukraine said on Friday its troops had broken through Russia’s first line of defences in several places, though they have then encountered even more heavily fortified Russian positions.

Deputy defence minister Hanna Maliar said Kyiv’s troops, in a much-vaunted counteroffensive against Russian forces, were advancing in the Zaporizhzhia region. Washington also said on Friday that Kyiv had made notable progress on the southern front in the last 72 hours.

“There is an offensive in several directions and in certain areas. And in some places, in certain areas, this first line was broken through. In some areas it was not broken through, the situation is different there,” Maliar said.

She added, however, that Kyiv’s troops who have been battling to advance through heavily-mined areas for almost three months had now run into major defensive Russian fortifications.

“Where we have already moved to the next line... the enemy is much more fortified there and, in addition to the mining, we also see concrete fortifications, for example, under the main commanding heights, and our armed forces have to overcome a lot of obstacles in order to move forward,” she said.