KYIV, Ukraine — The Ukrainian capital was blanketed by darkness Monday, even as residents were bolstered by a sense that their American allies had — finally — seen the light.

President Joe Biden has authorized Kyiv to use U.S. weapons for strikes deep inside Russia, according to two U.S. officials — a major policy shift that drew a furious response from the Kremlin on Monday, accusing the administration of pouring “oil on the fire” two months before President-elect Donald Trump takes office.

Crucially for Ukraine, the decision comes after months of pleading and just as Russia has intensified a wave of aerial attacks that forced widespread blackouts and killed more than a dozen people, according to local officials.

“It is excellent news for us and a significant move,” Kyiv resident Maryna Vlasenko, 39, told NBC News.

She also bemoaned the lengthy process and the continued limits on Ukraine’s use of the long-range weapons, however. “Sometimes I just have a feeling that we are receiving the bare minimum in order not to die, and with such an attitude, Ukraine will bleed to death,” Vlasenko said in an interview Monday.

“But it is better to have such a decision now than not having it at all.”

The U.S. has for months rebuffed Kyiv’s pleas to lift the restrictions on its usage of the Army Tactical Missile Systems, or ATACMS, in the Kursk border region of Russia. But with Kim Jong Un sending thousands of North Korean troops to help the Kremlin’s forces retake land there occupied by Ukraine, the U.S. ally will now be able to use the weapons in and around Kursk.

Moscow is not just pressing on the battlefield.

It has also ramped up its aerial assault against its neighbor with days of widespread attacks hitting civilian targets and critical infrastructure ahead of winter.

At least 11 people, including two children, were killed in the northeastern Ukrainian city of Sumy on Sunday, local officials said. And 10 people were killed in the historic southern city of Odesa, local officials said Monday.

Dozens more people were reported injured in the missile and drone strikes, which President Volodymyr Zelenskyy called “one of the largest and most dangerous” attacks of the entire war. They also hammered Ukraine’s power grid, leading the state operator to announce rolling power cuts in areas across the country on the eve of the 1,000th day since Russia launched its full-scale invasion.

“The week was just awful and terrifying,” Vlasenko said in Kyiv. “I don’t have tears to cry any more, it is pure pain. I am afraid we will stay with no electricity and water again this winter. We are exhausted.”

A battlefield boost?

While the White House has not publicly confirmed the reversal, the Kremlin said that if true it would amount to a “new leap of tension and a qualitatively new situation with regard to the U.S. involvement in this conflict.”

“It is clear that the outgoing administration in Washington intends to take steps, and they have talked about this, to continue to pour oil on the fire and continue to provoke further escalation of tension around this conflict,” spokesman Dmitry Peskov told reporters Monday.

Russian media also blasted the move, with government newspaper Rossiyskaya Gazeta saying Sunday that Biden had taken “one of the most provocative, ill-considered decisions” of his time in office, “which risks catastrophic consequences.”

Trump’s nominee for national security adviser, Rep. Mike Waltz, also appeared to raise concerns. In an interview Monday morning on “Fox & Friends,” the Florida congressman said: “It’s another step up the escalation ladder. And nobody knows where this is going.”

Despite the warnings and protestations, however, analysts said it was unlikely that the U.S. decision would either provoke major escalation from the Kremlin or do significant damage to the Russian military’s positions on the front lines, which have broadly been improving with each passing day.

“It’s too little and too late,” said Michael Bociurkiw, a nonresident senior fellow at the Atlantic Council’s Eurasia Center. “They’re trying to bomb Ukrainians into the dark ages,” he said in an interview from Kyiv. “How much worse could it get now?”

Frank Ledwidge, a former British military intelligence officer, agreed.

“It is unlikely that a few dozen of these flung into some tactical positions are going to tip anything,” said Ledwidge, a senior lecturer in war studies at England’s University of Portsmouth. “This is sort of a last hurrah from the Biden administration, perhaps even a vindictive one.”

Still, Ukrainians largely welcomed the news of a freer rein to make the most of U.S. help — especially given Trump’s impending return and the doubts in Kyiv about his commitment to backing their fight.

“It’s better late than never,” said Vladyslav Faraponov, head of the Institute of American Studies, a nongovernmental organization in Kyiv. “The decision is definitely overdue. However, that doesn’t mean Ukraine won’t make the best of it,” he said.

“There are still more than two months before Donald Trump’s inauguration,” Faraponov said. “Ukrainians don’t have the luxury of waiting while Russia continues killing civilians in Mykolaiv, Sumy, and pushing on the eastern front,” he added.

Daryna Mayer reported from Kyiv, and Mithil Aggarwal from Hong Kong.