KYIV, Ukraine — After years of resisting providing Ukraine with some of the West’s most high-powered weaponry, Britain indicated on Saturday that it would give battle tanks to Ukrainian forces to help prepare them for anticipated Russian assaults this spring.
Prime Minister Rishi Sunak of Britain told President Volodymyr Zelensky of Ukraine about his “ambition” to provide British main battle tanks and additional artillery systems, according to a statement from Downing Street. Before the British statement, Mr. Zelensky thanked Mr. Sunak for “the decisions that will not only strengthen us on the battlefield, but also send the right signal to other partners.”
The British Challenger IIs would be the first Western-made battle tanks to be sent to Ukraine since Russia invaded in February. Officials in the United States and Europe have long worried that sending tanks and other powerful weapons that would substantially increase Ukraine’s ability to hurt Russian forces could prompt President Vladimir V. Putin of Russia to escalate the conflict, even by potentially attacking Western targets or deploying small-scale nuclear weapons.
But that calculus has begun to change in recent weeks, as Western officials worry that time is tight to help Ukraine prepare for an anticipated Russian offensive this spring and, some say, a counteroffensive of its own. They have become more willing to take risks, in part because the Ukrainians have performed well on the battlefield and used other sophisticated Western weapons capably and within limits set by their allies.
Kyiv has been pleading for Western tanks almost since the start of the war to supplement its Soviet-era and Russian-made tanks and those supplied by other countries in Eastern Europe. Those tanks are wearing out fast after months of battle, and are also running low on ammunition that is no longer in production.
The push to satisfy Kyiv’s pleas gained speed this week as the British and Polish governments publicly urged a change in the Western alliance’s stance. The British announcement could increase pressure on Germany to send its coveted Leopard 2 tanks to Ukraine, or at least to allow other European countries that have those German-made tanks to give them to Ukraine. Poland said this week that it would send some of its German-made tanks, although Berlin would need to allow it.
Designed more than a century ago to break through trench warfare, tanks combine firepower, mobility and shock effect. Armed with large cannons, moving on treads and built with more protective armor than any other weapon on a battlefield, tanks can cross rough, muddy or sandy terrain where wheeled fighting vehicles might struggle.
In Ukraine, officials say armored vehicles — including the infantry fighting vehicles that France, Germany and the United States said last week they would send to Ukraine — will play a key role in battles for control of the fiercely contested towns and cities in the eastern provinces that border Russia. Ukraine’s most senior military commander, Gen. Valery Zaluzhny, has said his military needs some 300 Western tanks and about 600 Western infantry fighting vehicles to make a difference.
The British news media has reported in recent days that only a small number of tanks, around a dozen, are being considered. And there are some weapons that Ukraine’s Western allies still refuse to send, including fighter jets and long-range missiles that could hit occupied Crimea and military targets inside Russia itself.
The Biden administration, while leading the coalition supplying Ukraine with weapons, is still holding back American-made M1 Abrams tanks, gas guzzlers that require constant upkeep and, in any event, are too scarce to spare, officials say.
Also on Saturday, Russia launched two waves of strikes far from Ukraine’s front lines, jolting residents out of two weeks of relative quiet during a festive holiday period.
One of the strikes tore into a nine-story apartment building in the city of Dnipro in central Ukraine, local officials said, killing at least nine people and injuring dozens.
Photos from the scene showed a massive fire burning in the aftermath of the strike, with significant damage to the residential building.
In Kyiv, the explosions caused by Russian missiles were heard minutes before air-raid sirens sounded in the city, a rare occurrence. Hours later, a countrywide air-raid alert was put into place.
The morning attack on Kyiv most likely involved ballistic missiles fired from the north, which is why the air-raid warnings came late, according to Col. Yuriy Ihnat, a spokesman for the Ukrainian Air Force.
The Ukrainian president’s office said the blasts were part of an “attack on critical infrastructure facilities” in the city. Sites across the capital were hit, but no casualties were immediately reported. Four missiles also hit an industrial area in the northeastern city of Kharkiv, the mayor, Ihor Terekhov, said in a statement posted to Telegram. Local media reports said the city had lost power.
Russian forces have intermittently hit Kyiv and other areas of Ukraine far from the front lines since October with large-scale missile and drone attacks that have mostly targeted electricity infrastructure and other key services. The attacks have crippled Ukraine’s power grid and left the country grappling with rolling blackouts.
Saturday’s strikes shattered a relative calm as Ukrainians celebrated Orthodox New Year, or Malanka, a traditional holiday that is aligned with the older Julian calendar rather than the newer Gregorian one.
After the first air-raid alert lifted in Kyiv on Saturday morning, residents returned to the streets, some emerging from subway stations where they had sought shelter.
Oksana Koloniets and Anna Chuplykhina said they had been alarmed to hear explosions before an air-raid siren had sounded.
“You always know that after the air raid alarm, there are going to be some troubles,” said Ms. Chuplykhina, 45.
Ms. Koloniets, 50, said the timing of the strikes, during a period of celebration, only added to worries that had persisted for many in the capital in recent weeks.
“I think it’s one of the elements of intimidation — to repress this festive mood,” she said.
Elsewhere, Ukrainian authorities denied Russian claims that the town of Soledar was under Russian control.
Pavlo Kyrylenko, the head of Ukraine’s military administration in the Donetsk region that includes Soledar, told the Ukrainian news media that there was still fierce fighting around the mostly deserted town.
Seizing Soledar would represent the biggest success for Moscow’s forces in months, and could give them new locations to place artillery for the battle for the larger nearby city of Bakhmut. It also could put pressure on Ukrainian supply lines that run toward Bakhmut.
But military analysts have cautioned that the town itself is of limited strategic value.
In Istanbul, a top aide to President Recep Tayyip Erdogan of Turkey suggested on Saturday that it could take more than six months for Sweden to do what is necessary to win Turkey’s support for its bid to join NATO.
The aide, Ibrahim Kalin, applauded an amendment to Sweden’s constitution that will allow it to issue stricter antiterrorism laws as a step toward meeting Turkish demands. But he said it could take until June for the Nordic nation to put in place the new laws.
Russia’s invasion of Ukraine prompted Sweden and Finland to seek membership in NATO, which would grant them protection from the alliance in the case of a Russian attack.
Joining NATO requires approval by all members, and Turkey has demanded that the two Nordic countries tighten their antiterrorism laws and extradite people Turkey considers criminals.
Turkey has accused Sweden of harboring people with ties to the Kurdistan Workers’ Party, or P.K.K., a Kurdish militant group that Turkey, the European Union and the United States consider a terrorist organization. Turkey is also seeking the extradition of others accused of links to an Islamic movement that Turkey considers be a terrorist organization but Western countries do not.
Swedish officials have said that they have made great efforts to meet Turkey’s demands but that they must act under their domestic laws.
Mr. Kalin acknowledged those constraints, but said that Turkey was not in a hurry and could wait until its demands are met.
“We are not in a rush here,” he said. “They are in a rush to join NATO.”
Megan Specia reported from Kyiv, Ukraine, and Ben Hubbard from Istanbul. Lara Jakes contributed reporting from Rome, and Emma Bubola from London.