North Korean troops are suffering heavy losses in the fighting in Russia's Kursk region and are facing logistical difficulties as a result of Ukrainian attacks, Ukraine's military intelligence said Thursday.

The intelligence agency, known under its acronym GUR, said that Ukrainian strikes near Novoivanovka inflicted heavy casualties on North Korean units. It said that as a result of Ukrainian attacks along the front line, North Korean troops also faced supply issues and even experienced shortages of drinking water.

Ukraine's President Volodymyr Zelenskyy said earlier this week that 3,000 North Korean troops have been killed and wounded in the fighting in the Kursk region. It marked the first significant estimate by Ukraine of North Korean casualties several weeks after Kyiv announced that North Korea had sent 10,000 to 12,000 troops to Russia to help it in the almost three-year war.

The casualty disclosure came as the Biden administration was pressing to send as much military aid as possible to Ukraine before President-elect Donald Trump takes over.

Ukrainian forces launched a foray into the Kursk region in August, dealing a significant blow to Russia's prestige and forcing it to distract some of its troops from eastern Ukraine, where they were pressing a slow-moving offensive.

The Russian army has been able to reclaim some of the territory in the Kursk region from Ukrainian forces but has failed to fully dislodge them.

At the same time, Russia has sought to break Ukraine's resistance with waves of strikes with cruise missiles and drones against Ukraine's power grid and other vital infrastructure.

The latest massive attack on Christmas morning involving 78 missiles and 106 drones struck power facilities and prompted Ukrainians to take shelter in metro stations on Christmas morning, Ukraine's air force said. It claimed to have intercepted 59 missiles and 54 drones and jammed 52 other drones.

On Thursday, Russia again attacked Ukraine with 31 exploding drones, 20 of which were shot down, while the other 11 didn't reach their target due to jamming, the Ukrainian air force said.

As part of the daily barrage, Russian forces also struck a central market in Nikopol in the Dnipropetrovsk region with a drone on Thursday, wounding eight people, according to local authorities.

Ukraine struck back with drone strikes of its own.

Ukraine's Center for Strategic Communications said Thursday that the country's military has struck a plant in Kamensk-Shakhtynsky in Russia's southern Rostov region that produces propellant for ballistic missiles.

"This strike is part of a comprehensive campaign to weaken the capabilities of the Russian armed forces to carry out terrorist attacks against Ukrainian civilians," it said in a statement.