Ukrainian utility crews had been working to restore new and vital injury to the nation’s power grid, officers mentioned on Saturday, after Russia launched a swarm of Iranian-made assault drones in a single day on the heels of an enormous barrage of cruise missiles, antiaircraft missiles and drones on cities throughout Ukraine.

The assaults had been one other blow to Ukraine’s already battered energy grid, which Russia has repeatedly focused in what navy analysts say is a technique of plunging the nation into chilly and darkness to decrease morale.

The strikes, the first heavy aerial assault in weeks, occurred as preventing on the bottom has intensified, with Ukrainian officers saying that Russian forces are mounting a serious new push to grab management of all the Donbas area of jap Ukraine.

Air-defense techniques destroyed 20 of the Shahed-136 drones from 6 p.m. to midnight, the Ukrainian Air Pressure mentioned in an announcement early Saturday. However three power services within the Dnipro area of southeastern Ukraine had been hit, together with one in Kryvyi Rih for the second time in a day.

The drone assault occurred after Russian forces fired greater than 100 missiles in a day of strikes throughout Ukraine, in what each Russia’s Protection Ministry and the Ukrainian air drive described as a “huge” assault. Twelve folks had been injured throughout the nation, in response to Ukraine’s State Emergency Service, and the state-owned energy utility mentioned that a number of thermal and hydroelectric energy vegetation had been badly hit.

The corporate, Ukrenergo, on Saturday referred to as the state of affairs “troublesome however beneath management,” saying that energy rationing had been put in place in some areas and that restore work was persevering with.

Kharkiv, in northeastern Ukraine, was hard-hit, in response to officers. The top of the regional navy administration, Oleh Syniehubov, on Saturday cited “intensive” injury to infrastructure and mentioned that emergency energy shutdowns can be in place for “a number of days.”

The assaults additionally disrupted operations at Ukraine’s nuclear energy vegetation, in response to the United Nations’ nuclear watchdog. It mentioned late Friday that “instability within the electrical grid” had triggered a reactor unit on the Khmelnytskyi plant in western Ukraine to close down, and that the ability output at two others vegetation had been diminished as a precautionary measure.

Because the struggle nears its first anniversary, Russia has been pouring troops and tools into jap Ukraine, within the early stage of what Ukrainian and Western officers say is anticipated to be a serious offensive.

Ukraine’s Western allies have been dashing to offer extra highly effective weapons in order that Kyiv can mount its personal offensive. The federal government of President Volodymyr Zelensky has reiterated its requires much more arms — and quicker supply.

Mr. Zelensky mentioned he had acquired “good indicators” from allies when he pressed his case for heavier weapons on a uncommon worldwide journey this previous week to London, Paris and Brussels.

“This is applicable each to long-range missiles and tanks, and to the subsequent degree of our cooperation — fight plane,” he mentioned on Friday in his nightly tackle. “However we nonetheless have to work on this.”

John F. Kirby, a White Home spokesman, on Friday predicted that the approaching weeks and months can be “troublesome and demanding” for Ukraine. He mentioned that whereas he had but to see a serious new offensive take form, “we’re anticipating that and, frankly, so are the Ukrainians.”

The US believes that President Vladimir V. Putin of Russia will “take benefit” of the winter months to “restock, resupply, rearm” for what may very well be renewed offensive operations within the spring, Mr. Kirby instructed a information briefing on Friday. “Because the climate improves, the preventing will most likely get extra vicious,” Mr. Kirby mentioned.

In current weeks, a number of the fiercest preventing has centered on the Russian-occupied metropolis of Kreminna and the Ukrainian-held metropolis of Bakhmut, that are about 30 miles aside within the Donbas area.

Ukraine’s navy mentioned on Saturday that Bakhmut — the place Moscow’s troops have been slowly closing in on very important provide traces — remained the principle focus of Russian forces, with 124 strikes and 54 “clashes” within the space over the previous day. Moscow sees town, which it has been bombarding for the reason that summer season, as a vital step towards its aim of taking all of Donbas.

Gen. Valery Zaluzhny, the highest commander of Ukraine’s Armed Forces, mentioned on Saturday that he had mentioned the fierce preventing within the east and total battlefield image in a telephone name with Gen. Mark A. Milley, the chairman of the Joint Chiefs of Workers.

“Regardless of fixed enemy strain, we proceed to carry Bakhmut beneath our management and take measures to stabilize the entrance line round this city,” he mentioned in an announcement, including that the “key to success” can be “an applicable quantity of weapons, tools and ammunition.”

Bakhmut’s strategic worth, navy analysts say, is as a crossroads for a number of the area’s highways. Capturing town wouldn’t assure that Russia might make main advances within the east, however it will higher place its forces to take action.

The battle for town has been one of many bloodiest of the struggle, billed as a “meat grinder” for the heavy casualties suffered on each side. Russia’s efforts there have been for a while largely spearheaded by fighters from the Wagner non-public navy firm, which has recruited prisoners into its ranks. Its founder, Yevgeny V. Prigozhin, is an in depth affiliate of Mr. Putin’s and is seen as wanting a victory in Bakhmut to enhance his political standing in Russia.

However with the battle grinding on, and Moscow wanting to notch its first vital battlefield victory in months, the Kremlin in current weeks has been flooding the realm with troops. Analysts say that common Russian forces are more and more distinguished round Bakhmut.

In a uncommon video interview launched on Friday, Mr. Prigozhin predicted that it may very well be a while earlier than Moscow achieves its navy goals within the Donbas area. “We might want to work for one and a half to 2 years,” he instructed Semyon Pegov, a Russian navy blogger.

Mr. Prigozhin additionally urged persistence when it got here to Bakhmut.

“It’s most likely too early to say that we’re shut,” Mr. Prigozhin mentioned, noting that Ukraine’s navy had been sending in further models. However, he added, “we’re managing very effectively.”

Ivan Nechepurenko contributed reporting.