Nearly 200 Russian troops entered Pokrovsk in the Donetsk region over the weekend after months of attempts to penetrate the key frontline city, the General Staff of the Armed Forces of Ukraine said Sunday.

Fighting in the area is “highly dynamic and intense” but Ukraine’s troops are not encircled and have managed to recapture some areas around the city and stabilize the situation, according to Kyiv.

Russia has been pushing hard to accelerate battlefield gains while Ukraine has fought desperately to prevent Moscow’s forces from breaking through, with both sides seeking to maximize their leverage ahead of potential ceasefire negotiations.

Ukraine’s President Volodymyr Zelenskyy said in an address late Sunday that the situation in Pokrovsk was “difficult” and fighting was “fierce,” adding that success in the strategically located city is “critically important.”

On Friday, Kirill Dmitriev, Russian President Vladimir Putin’s special presidential representative for investment and economic cooperation, said Kyiv, Moscow and Washington were “quite close” to a deal on a ceasefire, after Zelenskyy said freezing the war along the current frontlines was “a good compromise.”

Kyiv and its European allies want U.S. President Donald Trump to put pressure on Putin to abandon his maximalist position of laying claim to large parts of the Donetsk region that his forces do not control, and accept a ceasefire along the current frontlines.

Putin has been dragging his feet on any potential ceasefire or permanent peace deal, dangling and then walking back the prospect of meeting with Trump and Zelenskyy, while continuing to accelerate his attempts to capture more of Ukraine.

Russia on Sunday even said it had successfully tested its nuclear-powered Burevestnik missile and is preparing to use it in battle.

That sparked a rebuke from Trump, who told reporters on board Air Force One: “And I don’t think it’s an appropriate thing for Putin to be saying either. By the way, he ought to get the war ended. A war that should have taken one week is now in its, soon, fourth year. That’s what he ought to do instead of testing missiles.”