A Ukrainian artillery unit firing toward Russian infantry troops advancing around the eastern Ukrainian town of Pokrovske on W

As the war drags on, Ukraine has managed to hold off Russian gains for the past month thanks in large part to continued support from the United States and its European allies, and help on the ground from partisans.

Following months of grinding war in which Ukraine has lost territory, Kyiv has been able to stem Russian advances recently and force Russia to sustain heavy losses, with up to 500 Russian troops killed or injured every day, according to some estimates.

John Spencer, a retired Army officer and chair of urban warfare studies for the Madison Policy Forum research institute, said that while Ukraine has lost tactical ground in some regions, its troops have succeeded in weakening Russia’s military.

ednesday.Credit...David Guttenfelder for The New York Times

“They have also made Russians expend resources that they can’t replenish,” Mr. Spencer said. “You don’t want to say they’re winning the war because there’s so much fighting to be done, but from really every measure you think about, especially geopolitically and militarily, they’re achieving outweighed gains.”

Russia still maintains a huge advantage in the size of its weapons arsenal, and Ukraine has suffered heavily over the course of the war. As many as 200 soldiers were being killed each day at one point; the civilian death toll has topped 5,000, according to United Nations estimates; and several of the country’s cities have been flattened. But Moscow has had no major territorial gains since the capture of the eastern Luhansk Province in late June.

Ukraine was bolstered on Thursday when the defense ministers of 26 countries, including Britain and Denmark, pledged about $1.55 billion in military aid to Ukraine. Ben Wallace, Britain’s defense minister, said the aid would include additional multiple-launch rocket systems and long-range missiles.

“We are not getting tired,” Mr. Wallace said of his country’s continued support for Ukraine.

Morten Bodskov, Denmark’s defense minister, said his country would not just help with weapons, but that it would also assist in training service members.

The aid, which Mr. Zelensky has called for repeatedly since the war began, added to another package from the United States that was announced earlier this week. The Pentagon said on Monday that it would send more ammunition in a new shipment of up to $1 billion worth of weapons and supplies. With that, the United States will have sent more than $9 billion in aid to Ukraine since Russia invaded the country on Feb. 24.