Lt. Denys Yaroslavsky, a Ukrainian intelligence officer, was visiting military positions near the Russian border on Friday when he met an artillery commander whose American-made howitzer was pointed toward Russia.
The commander was in a buoyant mood, Lieutenant Yaroslavsky said, recounting the episode. Russian territory was within range. “He was happy, and he said, ‘Now we can finally hit them.’”
For weeks Ukrainian officials had cited the need to remove the shackles on their commanders as they appealed to allies to allow a more effective defense, using Western weaponry. That consent finally came in a significant way on Thursday when the United States amended its policy after months of resistance, saying Ukraine could use American-provided weapons to hit military targets in Russia.
The shift is narrow in scope, granting Ukraine permission to use American air defense systems, guided rockets and artillery to fire into Russia only along Ukraine’s northeastern border. Fighting has been raging there near the city of Kharkiv for the past three weeks after Russian troops poured over the border to open a new front in the war.
But hitting targets with American weapons inside Russia had been a red line drawn by the Biden administration because of worries about escalation into a broader conflict. Ukrainian officials tried to assuage that fear by framing the use of Western weapons as a purely defensive tactic, pointing out how Russia has been launching missiles and gathering forces in the safety of its own territory, out of range of Ukraine’s Soviet-era weaponry.
Indeed, in granting permission, U.S. officials said the weapons should be used only in self-defense in the border region.
The peril to civilians near the border was underscored once again on Friday when a Russian missile tore into an apartment block in Kharkiv in the early morning, killing three and wounding two dozen more, including a medic and a police officer, regional officials said.
Ukraine hopes the reversal in policy will be pivotal in helping it regain its footing in a war that Russia is now dominating. It was a historic moment for the United States as well: It appeared to be the first time an American president had allowed the limited use of American weapons to strike inside the borders of a nuclear-armed adversary.
At a news conference in Sweden, President Volodymyr Zelensky of Ukraine called the decision “a step forward” to the goal of defending “our people who live in the villages through the borderline.”
Lieutenant Yaroslavsky, the intelligence officer, said he had met on Friday with fellow commanders who felt buoyed by the Biden administration’s decision. He said his understanding was that Ukraine had permission to launch strikes stretching to about 24 miles inside Russia.
This range, he said, will allow Ukraine to hit garrisons for Russian troops, logistics hubs for weaponry and ammunition depots but not the airstrips Russia uses to send bombers headed toward Ukraine, which are farther from the border. A number of weapons systems from NATO allies, including M777 howitzers from the United States, are already positioned within range of Russian territory, he said.
Speaking Friday afternoon, Lieutenant Yaroslavsky declined to clarify if Ukraine had already opened fire into Russia.
Other officers also welcomed the decision. “Do the Ukrainian defense forces know from where the occupier is attacking Kharkiv?” said Col. Yurii Ihnat, a Ukrainian Air Force officer, referring to the launch sites of missiles across the border in Russia. “Obviously, we do,” he said in a text message, noting that until now Ukraine had been unable to strike back.
Russian officials have been proclaiming all week that NATO countries risk escalation if they provide Ukraine greater freedom to shoot into Russia. On Friday, Dmitri S. Peskov, the Kremlin spokesman, claimed Ukraine had earlier in the war fired American weapons into Russia and “it proves the extent to which the U.S. is involved in this conflict.”
With nearly every new Western weapon system delivered in a show of support for Ukraine’s war effort, Russia has threatened ominous consequences for the West, though so far it has not delivered any.
Bending to Russian threats of escalation, said Col. Roman Kostenko, the chairman of the defense and intelligence committee in Ukraine’s Parliament, would only signal “weakness” by Europe and the United States. That would surely be noticed in other contexts in the world, he said, including the tensions between China and Taiwan.
He said the policy shift was needed to deter attacks elsewhere along the Ukrainian border. Russia could swiftly mass troops at any point, he said, and “it’s important to hit them before they cross.”
Ukrainian officials had said allowing the use of Western weaponry could help turn the tide of the fighting along the border and defend against attacks on Kharkiv, whose city center is just 24 miles from Russia, by hitting missile launchers and airplanes inside Russian territory.
The Russian missile strike on an apartment block in Kharkiv happened on Friday just hours after American officials announced the change in policy. A fire broke out, and a few minutes after the first missile hit, another struck the same location in a tactic known as a double tap, which is intended to target emergency responders.
For residents of Kharkiv, the bombardments are a menace overshadowing most aspects of their lives.
The short trajectories of the bombs and missiles mean civilians have little warning, or sometimes none at all, leaving them with no choice but to sleep and go about their days knowing that they could be hit by a missile at any time.
“It was all instantaneous,” said Andriy Kolenchuk, a production manager at a printing company hit on May 23. Explosions rang out, the lights blinked off and debris fell from the ceiling, he said. Dust and smoke swirled about, and “everybody was running around covered in blood.”
The city’s vulnerability had fueled Kyiv’s frustration with Western hesitation.
Officials in Britain, France, Poland and Sweden had already voiced support for the use of their countries’ weapons to strike inside Russia before the Biden administration shifted its stance, and NATO’s secretary general, Jens Stoltenberg, had spoken in favor of allowing Ukraine to use weapons from members of the alliance to strike targets within Russia
Ukraine has been striking targets deeper in Russian territory with a homegrown fleet of long-range exploding drones. The American weapons would help Ukraine’s army in the ground fighting north of Kharkiv and Ukraine’s air defense forces in defending the city of Kharkiv, Ukrainian officials said before the announcement in Washington.
Also on Friday, Russia and Ukraine announced the release of 75 prisoners from each country, the first such exchange since February, and a rare example of dialogue between the warring nations. “We remember everyone. We make every effort to find each and every one,” Mr. Zelensky wrote on social media.
Direct communications between Moscow and Kyiv have been infrequent since the early days of the war, but the two sides have regularly exchanged prisoners of war through deals often brokered by third parties such as the U.A.E. or Turkey.
Ukraine’s Coordination Headquarters for the Treatment of Prisoners of War said on Friday that there had been 52 exchanges in total, including Friday’s, with 3,210 Ukrainians returned. Russia has not disclosed a total number.
Maria Varenikova contributed reporting from Kharkiv, Constant Méheut from Kyiv, Ukraine, and Ivan Nechepurenko from Tbilisi, Georgia.
