Last week, German and French officials discussed a buildup of Russian forces near the city, people familiar with the discussions told Bloomberg.
On Friday, Ukrainian President Volodymyr Zelensky said that Russia had deployed 100,000 troops to the area.
Pokrovsk is a key transportation hub for Ukrainian forces in Donbass. Its fall could open the way for Russian troops to attack the last major Ukrainian-held cities in the Donetsk region: Slavyansk and Kramatorsk.
The industrial city in eastern Ukraine was the main declared target of the bloody Russian offensive launched more than a year ago.
The Russian attack towards Dobropilje was on a narrow front and, if consolidated, would make it even more difficult for Ukrainian forces to supply the Pokrovsky salient, according to reports.
Russian forces came within 8-10 kilometers of Pokrovsk in August and September 2024, but failed to capture it and attempted to encircle the city this year.
In mid-August, Russian troops made a brief breakthrough north of Pokrovsk, advancing about 10 kilometers near Dobropolje before being pushed back by Ukrainian units.
The summer offensive resulted in minimal gains, with Moscow capturing only 2,033 square kilometers (785 sq mi), or 0.3% of Ukraine's territory.
Speaking in Beijing on Wednesday after watching a military parade with Chinese leader Xi Jinping and North Korean leader Kim Jong Un, Putin said he would continue to fight if a peace deal was not reached.
He praised the progress of Russian forces, claiming that they are advancing"on all fronts" and that they have weakened the Ukrainian army.
If there is no peace agreement, he said,"then we will have to solve all our tasks militarily".
Zelensky, who arrived in Paris the same day for talks with European allies, said he had seen no signs that Moscow was serious about ending the war.
With no sign of a Russian pullback, Ukraine and its allies are working to bolster Kiev's military.
German Chancellor Friedrich Mertz called the effort"the most important security guarantee we can provide," while European Commission President Ursula von der Leyen said Ukraine must become "a steel porcupine that is indigestible to potential invaders."
European countries finance the purchase of American weapons, and Zelensky hopes for billions of dollars in monthly purchases.
Last week, the US approved the sale of 3,350 missiles with a range of up to 450 kilometers (280 miles), worth $825 million.
Ukraine is also developing new weapons at home, including the Flamingo cruise missile, capable of flying 3,000 kilometers (1,900 miles), and using artificial intelligence to coordinate drone swarm attacks.
