In an article for The Economist published on Wednesday, General Valery Zaluzhnyi said his army needed key new military capabilities and technological innovation to break out of the new phase of the war, now in its 21st month.

Using stark language, he described risks of prolonged, attritional fighting: “This will benefit Russia, allowing it to rebuild its military power, eventually threatening Ukraine’s armed forces and the state itself.”

His article comes almost five months into a major Ukrainian counteroffensive that has not made a serious breakthrough against heavily mined Russian defensive lines. Fighting is expected to slow as the weather worsens.

Russian troops have gone on the offensive in parts of the east and Kyiv fears Moscow plans to unleash a campaign of air strikes to cripple the power grid, plunging millions into darkness in the depths of winter.

“Just like in the First World War we have reached the level of technology that puts us into a stalemate,” Zaluzhnyi was quoted as saying in an interview published alongside his article.

The article singled out Russia’s air power advantage as a factor that made advancing harder and called for Kyiv to conduct massive drone strikes to overload Russia’s air defences.

“Basic weapons, such as missiles and shells, remain essential. But Ukraine’s armed forces need key military capabilities and technologies to break out of this kind of war. The most important one is air power,” he wrote.

He said Ukraine must get better at destroying Russian artillery and devise better mine-breaching technology, saying Western supplies have proven insufficient faced with Russian minefields that stretched back 20 km (12 miles) in some areas.

He called it a priority for Ukraine to build up its reserve forces despite noting it had limited capacity to train them inside the country and highlighting gaps in legislation that allowed people to evade service.

“We are trying to fix these problems. We are introducing a unified register of draftees, and we must expand the category of citizens who can be called up for training or mobilisation,” he wrote.

“We are also introducing a ‘combat internship’, which involves placing newly mobilised and trained personnel in experienced front-line units to prepare them,” he said.