Small Russian units have breached Ukrainian lines in eastern Donetsk in one of the most significant advances in the region over the past year, Ukrainian officials said Tuesday.

The push comes ahead of Friday’s planned meeting between Russian President Vladimir Putin and U.S. President Donald Trump in Alaska.

DeepState, a Ukrainian battlefield monitoring group, reported advances of about 10 kilometers (6 miles) in two prongs toward the coal mining town of Dobropillia, targeting villages between Kostyantynivka and Pokrovsk. 

“The situation is quite chaotic, as the enemy, having found gaps in the defence, is infiltrating deeper, trying to quickly consolidate and accumulate forces for further advancement,” DeepState said.

Elsewhere in the region, Ukraine’s military warned of “heavy defensive battles against superior enemy forces.”

“In the Pokrovsk direction alone, the occupiers have concentrated a group of more than 110,000 personnel,” the Ukrainian General Staff said in an update Tuesday evening, adding that additional forces and resources are being deployed to bolster defenses in certain areas.

Ukrainian President Volodymyr Zelenskyy confirmed in a Tuesday briefing that “Russians have advanced about 10 kilometers (6 miles) in several places.” He added that Russia is “preparing for an offensive operation” in three directions: Zaporizhzhia, Pokrovsk, and Novopavlivka.

Zelenskyy explained that the offensive aims to build momentum ahead of the summit.

“The task of this advance is clear to us,” he said, noting that Russia is trying to create a misleading impression before the Putin-Trump meeting “that Russia is moving forward, advancing, and Ukraine is losing.”

Zelenskyy said that the overall manpower ratio favors Russian troops three to one but noted that Russia’s losses are also three times higher than Ukraine’s.

The Institute for the Study of War said it is too early to call the advance a breakthrough but warned that the coming days will be critical to preventing deeper Russian gains.