Ukraine reported on Friday that its soldiers had breached Russia’s first line of defense in many spots, but they were subsequently met with even more highly built Russian positions.

According to Deputy Defense Minister Hanna Maliar, Kyiv’s soldiers are advancing in the Zaporizhzhia area in a much-touted counteroffensive against Russian forces. On Friday, Washington also stated that Kyiv had achieved significant progress on the southern front in the previous 72 hours.

“There is an offensive in several directions and regions. And this initial line was broken through in some places, in certain sections,” Maliar told Ukrainian television.

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.

“Our armed forces have to overcome a lot of obstacles in order to move forward,” she said.

Heavy fighting swept the villages around Bakhmut in eastern Ukraine, captured in May by Russian forces after months of battles, Maliar said but added it was difficult to determine whether any advances had been made.

“In the course of a single day, positions between the two sides can change several times.”

The General Staff of Ukraine’s Armed Forces in its evening report on Facebook said that Russian forces had made no headway in attempts to advance in five different sectors of the front — from Kupiansk in the northeast to different parts of Donetsk region.

In Washington, White House National Security Council spokesman John Kirby said the United States had “noted over the last 72 hours or so some notable progress by Ukrainian armed forces …in that southern line of advance coming out of the Zaporizhzhia area”.

“They have achieved some success against that second line of Russian defenses”, Kirby said, adding it was up to Ukraine how to capitalize on that success.

Ukraine’s counteroffensive has retaken more than a dozen minor villages but has yet to regain any big settlements. It took Robotyne hamlet last week, beyond which lay Russian-occupied high ground, massive anti-tank trenches, and lines of concrete defenses visible from orbit.

Russia has already labeled the Ukrainian advance a failure; Kyiv claims it has been moving slowly on purpose to reduce losses, and that its work is made more difficult by the absence of air power that its Western friends take for granted.

This week, Kyiv reacted angrily to press stories quoting anonymous US officials worrying about the country’s poor development. Some fear that the West’s steadfast backing may dwindle when colder and wetter weather impede progress on the battlefield later this year.

Ukrainian President Volodymyr Zelenskiy is expected to attend the annual gathering of world leaders at the United Nations in New York this month and take part in a U.N. Security Council meeting on Ukraine, Albania’s U.N. Ambassador Ferit Hoxha told reporters on Friday.