President Volodymyr Zelenskiy says Kyiv's troops were "moving forward" in their counteroffensive against Russian forces, rebuffing Western officials who say Ukraine is gaining ground too slowly.
The much-vaunted counteroffensive, which is approaching the three-month mark, has retaken more than a dozen villages but no major settlements with soldiers hampered by vast Russian minefields and defensive lines.
This week, unnamed United States officials vented frustration at the slow progress of the operation and even faulted Ukrainian strategy, according to Western reports that drew Kyiv's ire.
"Ukrainian forces are moving forward," Zelenskiy wrote on the Telegram messaging app.
"Despite everything, and no matter what anyone says, we are advancing, and that is the most important thing.
"We are on the move."
Some fear the West's support could begin to falter as colder and wetter weather slows progress on the battlefield later in the year.
The West has poured in many billions of dollars to help the counteroffensive and Kyiv says it needs more.
Ukrainian battlefield momentum has picked up slightly in one part of the southeastern Zaporizhzhia front where Deputy Defence Minister Hanna Maliar said on Friday Kyiv's troops had broken through the first line of Russian defences.
The White House said there had been "notable success" by Ukraine in the area, although Maliar warned Kyiv's troops had reached even more heavily fortified positions on the other side after breaking through.
In its daily battlefield update, the Ukrainian military reported no new breakthroughs but said its troops continued to advance towards Melitopol, a major Russian-occupied urban centre in the Zaporizhzhia region.
It reported 45 combat clashes on the frontlines in the past 24 hours and said fighting raged in the east where Ukrainian troops had repelled multiple Russian attacks.
Russia has already described the Ukrainian counteroffensive as a failure.
Kyiv says it has been advancing slowly on purpose to minimise losses, and its advance has been greatly complicated by its lack of modern air power.
It comes as the Russian Defence Ministry said on Saturday it had brought down three Ukrainian drones over the Belgorod region, while the regional governor said one man had been killed in a Ukrainian rocket strike on a village close to the border.
Separately, the governors of the nearby frontier regions of Bryansk and Kursk said a string of border villages had come under fire from Ukraine, and a woman had been wounded in the Kursk region.
Ukrainian drone attacks on Russian territory have picked up in recent weeks, with dozens of drones striking Russia at once on some days, reaching as far as the western city of Pskov, 600km from Ukraine.
Russian-installed authorities in the Moscow-controlled part of Ukraine's Kherson region also said on Saturday that Kyiv struck the village of Maslivka in a drone strike, wounding a civilian.