Ukrainian troops have established a foothold on the eastern bank of the Dnipro River, officials from Russia and Ukraine have acknowledged, in an operation that Kyiv says will open new avenues of attack toward Crimea. Estimates of the number of Ukrainian troops involved range from dozens to several hundred and they are reported to be engaged in heavy fighting with Russian forces on the far side of the river. In Ukraine’s first official confirmation of the beachhead, Andriy Yermak, the head of Ukraine’s presidential administration, said the crossing showed that Kyiv was still making advances in a months-long counteroffensive that has so far failed to yield major territorial gains. “Against all odds, Ukraine’s defence forces have gained a foothold on the left [east] bank of the Dnipro,” Yermak said in his address, a transcript of which was posted on the website of Ukraine’s president, Volodymyr Zelenskiy. “Step by step, they are demilitarising Crimea,” he said. “We have covered 70% of the distance. And our counteroffensive is developing.” Russian troops abandoned the western bank of the Dnipro River a year ago and took up positions on the eastern side, from which they have been regularly shelling towns and villages opposite. Officials told the Guardian earlier this month that somewhere between a few dozen and a few hundred troops were holding a toehold on the opposing side of the river as part of an operation that had begun in mid-October. They had faced heavy bombardment from Russian artillery and drones. A report in the Wall Street Journal on Wednesday said Ukrainian marines were reinforcing positions in three villages on the eastern bank of the river, including with armoured Humvees and at least one infantry fighting vehicle, and had cut off one road that Russians used to resupply troops in the area. Nonetheless, it said the troops described themselves as “hunkered down in basements and trenches and heavily outnumbered”. The Ukrainian announcement came as Kyiv has sought to maintain western support for a war that some of its own top commanders have described as approaching a stalemate. Among them were the Ukrainian army commander-in-chief, Valerii Zaluzhnyi, who told the Economist in a controversial interview that “there will most likely be no deep and beautiful breakthrough”. Yermak’s speech appeared to push back at the idea that the war had stalled, saying Zelenskiy had a “clear plan” for victory. “Among the priorities, he identifies the development of our defence industry and the deployment of our own arms production,” he said. “But that will be later. Meanwhile, we need weapons right now.” Ukraine’s counteroffensive still appears far from having achieved its stated aims, with little progress in the south and heavy fighting continuing near Avdiivka and Bakhmut in the east. Sam Cranny-Evans, an associate fellow at the Royal United Services Institute, said the Dnipro River advance might “buy some breathing space”. “The Russians appear to be gaining momentum in other areas such as Avdiivka, which is also drawing in Ukrainian troops and creating issues. At this stage, I think it is more of an opportunistic effort designed to shape the battlefield for future operations and restore some offensive prestige,” he said. “To convert it into a war-changing success, they will need to find a way to get a lot more equipment and personnel across the river. The longer it takes to do that, the more attrition they are likely to suffer without achieving anything significant.” On Wednesday, a Russian-backed regional official confirmed that Ukrainian troops had crossed the river, urging calm and claiming that additional Russian forces were being deployed to repel the attack. Vladimir Saldo, the Moscow-installed head of the occupied Kherson region, claimed there were just a few dozen Ukrainian troops on the left bank of the river and that they had managed to cross by “sending more [people] than we had means to destroy”. The exact numbers of Ukrainian soldiers to cross the river and the number of casualties on both sides remains unclear. Russia last week claimed to have killed hundreds of Ukrainian soldiers attempting to establish a bridgehead, but it offered no evidence. On Monday, Russian state news agencies published reports that Moscow was moving its troops east of the Dnipro River to “more favourable positions”, using language that it has employed in the past to describe major retreats in Kherson and in the Kharkiv region in northern Ukraine. Moments later, the reports were retracted and the Russian defence ministry claimed it had been the target of an information attack.