KHARKIV REGION, Ukraine — Ukrainian attacks on Russian supply lines have left Russian units scrambling for food, water and ammunition, blunting Moscow’s renewed invasion into Ukraine’s northeast Kharkiv region, according to Ukrainian field commanders who shared radio and phone intercepts and results of their interrogations of Russian prisoners of war.

       The intercepts and extensive interviews with 10 Ukrainian commanders and troops operating across the front line in Kharkiv — including several who monitor Russian communications and who question POWs immediately after they are captured — paint a picture of increasingly desperate Russian ground troops who are losing personnel and momentum after reinvading across the border in May.

       In the transcript of one radio conversation, intercepted in June and shared with The Washington Post, a Russian soldier orders another to ensure incoming troops responsible for carrying supplies understand that there is a dire shortage of food and water.

       “Tell each of them … not to listen to the [expletive] guide who says that ‘Water is not needed, food is not needed, everything is here,’” the soldier says. “There is nothing here.”

       The Post could not independently confirm the veracity of the audio and transcripts but received them directly from troops monitoring the communications. Nearly all of the Ukrainian soldiers interviewed for this article spoke on the condition that they be identified only by first name, in accordance with military rules.

       Russia’s military, which far outnumbers Ukraine’s, remains at a strong advantage in the region, supported by hundreds of enormous glide bombs smashing weekly into Ukrainian positions across the front line. But Ukrainian troops have largely prevented major Russian territorial gains. According to British intelligence analysts, Russia in May suffered its highest number of daily casualties since the invasion began in February 2022, with at least 1,200 Russian troops killed or wounded each day.

       The steep losses and degraded condition of Russian units on the front show how Moscow’s invasion of Ukraine has resulted in a grinding war of attrition with major territorial shifts unlikely between now and November when the Kremlin sees a chance that a Donald Trump victory in the U.S. presidential election could lead to a reduction in Western military aid for Ukraine.

       In the Kharkiv region, Russian forces initially appeared poised to overrun the poorly fortified border region. Russian President Vladimir Putin said that his goal was to create a buffer zone that would limit Ukrainian strikes on cities and towns in Russia. That also could have put the Russians within artillery range of Kharkiv, Ukraine’s second largest city, potentially allowing them to encircle it.

       But Ukraine’s defenses were buoyed in part by a White House decision to allow certain U.S. weapons to be used to strike inside Russia. The Ukrainians used American weapons to hit Russian air defenses, forcing the Russians to pull back some batteries. The Ukrainians also carried out coordinated attacks on Russian supply routes using drones and artillery.

       The intercepted communications shared with The Post show that Russia now faces significant difficulty securing sufficient supply routes to serve the basic needs of its troops.

       In one communication, a Russian soldier speaks to his parents, telling them he is positioned near the Ukrainian village of Lyptsi, where his unit lost several men and ran out of food.

       “We had nothing to eat, but we found a jar of wine and drank it for two days,” the soldier said on the call, which Ukrainian troops recorded.

       Another communication suggested troops were unwilling to move forward. “I am without orders,” one soldier says, describing troops who are “refusing.”

       The intercepts, along with drone footage, provide critical intelligence as Ukrainian forces, outnumbered and outgunned, plan their next moves and assess the impact of their attacks.

       Despite being stopped well short of encircling Kharkiv city, Russia’s objectives seem not to have changed, with Moscow’s forces still focused on seizing the village of Lyptsi, an important logistical hub that would also allow them to use hilltops for firing advantage, officials said.

       Col. Maksym Golubok, 42, chief of staff of Ukraine’s 13th National Guard Brigade, said that since Washington lifted restrictions on hitting targets across the border, Russia has stopped massing large groups of troops in the border area and has moved some artillery systems away to protect them.

       “They don’t gather people in one place. They operate in small units,” Golubok said in an interview. “We eliminate one soldier at a time, not entire units.”

       Still, relentless glide bombs pose the greatest threat to Ukrainian troops. Between early May and late June, Golubok said, more than 660 bombs hit his brigade’s positions in the Kharkiv region.

       Dmytro, 29, a Ukrainian soldier responsible for monitoring Russian communications, said that Russian soldiers previously used motorcycles and buggies for supply runs. But after Ukraine, using drones, mined roads and hit supply vehicles, Russian soldiers are moving mainly on foot.

       Ukrainian troops are also delivering supplies on risky ground missions, as well as by air using agricultural drones that carry heavier payloads.

       Due to constant Ukrainian surveillance, Russian troops are moving in short bursts, taking cover frequently, Dmytro said, so a five-mile journey for food and water could take three days or longer.

       “If we disrupt the routes they use for food and supplies, we won’t need to go on assault — they’ll just leave the positions,” he said, speaking from a different underground command center north of Kharkiv where wall-mounted screens showed live bird’s eye views of Russian positions.

       Andrii Shcherbyna, 42, a soldier in Ukraine’s 57th brigade, said that while on front-line missions, he drinks two to three liters of water a day. From intercepts, Shcherbyna said he understood Russian troops are rationing water, drinking just 250 milliliters each.

       “Our main target is not let the Russians establish supply routes,” he said. “If you cut water and food, they’re in a very bad condition.”

       Some Russian soldiers are now holed up in a factory in Vovchansk, a town Russia invaded in May where street battles continue to occur, Ukrainian officials said.

       In June, Ukraine cut off supplies by surrounding the factory, which is the tallest building in the area and fortified by thick walls.

       Despite initial plans to flood the area with reinforcements, Russia has been unable to reach the factory, Ukrainian troops said. Storming it would be difficult, so Ukrainian troops focus on blocking supply routes.

       Vitalii, 23, one of the Ukrainian troops working in intense 24-hour shifts monitoring the factory from a destroyed civilian house nearby, said there could be anywhere from dozens to more than 100 Russian soldiers inside. “Our responsibility is to control the road to cut off supply,” Vitalii said.

       Russia has also tried — often unsuccessfully — to deliver supplies by drone, Vitalii said.

       Each journey to and from Vitalii’s position could be his last. To get there, Ukrainian soldiers leave their vehicles some distance away, then move on foot for hours under intense attack. Knowing they have trapped Russian troops inside is worth it, said another soldier, Roman, 35.

       “I don’t think they thought they’d be in this position,” Roman said.

       Intercepted information is so valuable that Ukrainian troops risk their lives to collect it.

       Andrii, 37, an infantry soldier who has spent weeks fighting on the most intense front lines, said he knew from such intelligence gathering that Russia “had a lot of injured and they had problems with food and water.”

       “They asked for resupply, but vehicles could not reach them,” Andrii said.

       Last month, after a street gun battle in Vovchansk, Andrii said he collected a green radio off the chest of a dead Russian soldier — the first time in two years of fighting that he found such a prize.

       Back at the destroyed civilian house where he was based, Andrii hung the radio on the wall. It was so loud that he spent 30 minutes trying to lower the volume so he could monitor Russian operations without giving away his own position with the noise.

       Then, for 12 hours, he listened as troops relayed their positions and plans. He reported the details to his own commanders, until the line went dead.

       The information helped thwart a planned Russian attack, Andrii said. “Ukrainian troops were waiting for them,” he said. “If you’re informed, you’re ready.”

       On a more personal level, listening to frantic Russian voices also boosted Andrii’s spirits. “It helped a lot to hear they’re panicking and in fear,” he said. “I could hear their fear, and it inspired me, because we’re also scared.”

       In this article, The Washington Post used [expletive] where profanity appears instead of its usual style because the profanity in Russian does not always directly translate into English.