KYIV, Ukraine: Russian strikes killed three people in the Ukrainian city of Kharkiv, the regional governor said early Friday, hours after the United States authorised Kyiv to use American weapons to hit targets inside Russia in defence of the embattled region.

With Russia having retaken the battlefield initiative in recent months, Ukraine had doubled down on calls to permit it to use longer-range US weapons to attack Russian territory -- something Washington had resisted over fears it could drag NATO into direct conflict with Moscow.

But that calculus appears to have changed since Russian forces launched a fresh offensive in the Kharkiv region this month.

A Russian missile strike in Kharkiv city killed three people and wounded at least 16 others, regional Governor Oleg Synegubov said in a post on Telegram early Friday morning, noting an emergency medic was among the wounded and an ambulance was damaged.

"The enemy again used a double strike tactic, while medics, rescuers and law enforcement officers were already working on the spot," Synegubov said.

Kharkiv Mayor Igor Terekhov said in an interview with local media there could be more people trapped under the rubble of the residential building, adding: "There was not a single military person, not a single military object" present.

Terekhov later put the number of wounded at 23.

Kharkiv, Ukraine's second-largest city, is located just across the border from Russia's Belgorod and regularly comes under attack from Russian missiles.

Russian strikes that hit a hardware superstore in the city last weekend killed 16 people.

Restrictions lifted US officials said Thursday that President Joe Biden had lifted restrictions on Ukraine using weapons supplied by the United States against targets on Russian territory, but only to defend the Kharkiv region.

"The president recently directed his team to ensure that Ukraine is able to use US-supplied weapons for counter-fire purposes in the Kharkiv region so Ukraine can hit back against Russian forces that are attacking them or preparing to attack them," a US official said on condition of anonymity.

A second US official confirmed the change of policy.

US Secretary of State Antony Blinken had hinted on Wednesday that Biden could change course.

Blinken, who visited Ukraine earlier this month, said the United States had "adapted and adjusted" as the "battlefield has changed" in remarks to reporters in Moldova on the eve of NATO talks in Prague.

Ahead of the NATO meeting, alliance chief Jens Stoltenberg had also said repeatedly that it was time for members to reconsider the limits on strikes inside Russia.

French President Emmanuel Macron appeared to shift the dial forward on Tuesday when he said Ukraine should be allowed to "neutralise" bases in Russia used to launch strikes.

German Chancellor Olaf Scholz, however, remained less sure, saying Ukraine should act within the law -- and Berlin had not supplied weapons that could hit Russia anyway.

German did, however, promise Ukraine a new package of military aid worth 500 million euros ($540 million) on Thursday, with the defence ministry saying it included "artillery, air defence (and) drones".

The Kremlin, for its part, accused the West on Thursday of "entering a new round of escalations in tensions" in recent days.

"They are provoking Ukraine in every possible way into continuing this senseless war," spokesman Dmitry Peskov told reporters during a daily briefing.