By SAMYA KULLAB and VASILISA STEPANENKO

KYIV, Ukraine (AP) — An overnight Russian missile and drone bombardment of Ukraine killed 15 people and injured 156, local officials said Tuesday, with the main barrage demolishing a nine-story Kyiv apartment building in the deadliest attack on the capital this year.

At least 14 people were killed as explosions echoed across the Ukrainian capital for almost nine hours, Kyiv City Military Administration head Tymur Tkachenko said, destroying dozens of apartments.

Russia fired more than 440 drones and 32 missiles, Ukrainian President Volodymyr Zelenskyy said, calling the Kyiv attack “one of the most terrifying strikes” on the capital.

“Our families had a very difficult night, one of the biggest attacks from the very beginning of this war,” he said after arriving at the G7 summit in Canada.

Ukraine’s Interior Ministry said 139 people were injured in Kyiv. Mayor Vitalii Klitschko said Wednesday would be an official day of mourning.

The attack came after two rounds of direct peace talks failed to make progress on ending the war, now in its fourth year.

Russia steps up aerial attacks

Russia has repeatedly hit civilian areas of Ukraine with missiles and drones. The attacks have killed more than 12,000 Ukrainian civilians, according to the United Nations. Russia says it strikes only military targets.

Russia has in recent months stepped up its aerial attacks. It launched almost 500 drones at Ukraine on June 10 in the biggest overnight drone bombardment of the war. Russia also pounded Kyiv on April 24, killing 12 people.

The intensified long-range strikes have coincided with a Russian summer offensive on eastern and northeastern sections of the roughly 620-mile front line, where Ukraine is short-handed and needs more military support from its Western partners.

Uncertainty about U.S. policy on the war has fueled doubts about how much help Kyiv can count on. Zelenskyy had been set to meet with U.S. President Donald Trump at the G7 summit Tuesday to press him for more help. But Trump returned early to Washington on Monday night because of tensions in the Middle East.

British Prime Minister Keir Starmer denied that Trump’s refusal to back new sanctions on Russia or provide U.S. security guarantees for Ukraine makes it all but impossible to compel the Kremlin to accept a ceasefire.

The U.K announced new sanctions Tuesday on Russia’s defense industry and its oil-carrying “shadow fleet” of about 500 ships of uncertain ownership that allowed Moscow to dodge sanctions. The announcement coincided with Zelenskyy’s arrival as a guest at the G7 summit.

Canadian Prime Minister Mark Carney also announced new sanctions on Russia’s shadow fleet and energy revenues, as well an additional $2 billion Canadian ($1.4 billion U.S.) in new funding for Kyiv for drones, ammunition, and armored vehicles. He called the latest attack “barbarism by Russia” that underscores the importance of standing in solidarity with Ukraine and the Ukrainian people.

Ukraine tries to keep the world’s attention

Zelenskyy is seeking to prevent Ukraine from being sidelined in international diplomacy. Trump said earlier this month it might be better to let Ukraine and Russia “fight for a while” before pulling them apart and pursuing peace, but European leaders have urged him to pressure Russian President Vladimir Putin into accepting a ceasefire.

Kremlin spokesman Dmitry Peskov said Tuesday it is unclear when another round of talks might take place.

Ukraine’s Foreign Minister Andrii Sybiha said Russia’s attacks during the G7 summit showed Putin’s “total disrespect” for the U.S. and other countries.

“Russia not only rejects a ceasefire or a leaders’ meeting to find solutions and end the war. It cynically strikes Ukraine’s capital while pretending to seek diplomatic solutions,” Sybiha wrote on social media.

Ukrainian forces have hit back against Russia with their own domestically produced long-range drones.

The Russian military said it downed 203 Ukrainian drones over 10 Russian regions between Monday evening and Tuesday morning.

Russian civil aviation agency Rosaviatsia reported briefly halting flights overnight in and out of all four Moscow airports, as well as those in the cities of Kaluga, Tambov and Nizhny Novgorod as a precaution.

Ukrainian shelling killed a 69-year-old man and a 57-year-old woman Tuesday in the border village of Zvannoye in Russia’s Kursk region, Gov. Alexander Khinshtein said.

Overnight Russian drone strikes also struck the southern Ukrainian port city of Odesa, killing one person and injuring 17 others, according to Oleh Kiper, head of the regional administration.

Putin “is doing this simply because he can afford to continue the war. He wants the war to go on. It is troubling when the powerful of this world turn a blind eye to it,” Zelenskyy said.

Russian attack demolishes apartment building

The Russian attack delivered “direct hits on residential buildings,” the Kyiv City Military Administration said in a statement. “Rockets — from the upper floors to the basement,” it said.

A U.S. citizen died in the attack after suffering shrapnel wounds, Interior Minister Ihor Klymenko told reporters.

Thirty apartments were destroyed in a single residential block after it was struck by a ballistic missile, Klymenko said.

“We have 27 locations that were attacked by the enemy. We currently have over 2,000 people working there, rescuers, police, municipal services and doctors,” he told reporters at the scene of one attack.

Olena Lapyshniak, 49, was shaken from the strike that nearly leveled her apartment building. She heard a whistling sound and then two explosions that blew out her windows and doors.

“It’s horrible, it’s scary, in one moment there is no life,” she said. “There’s no military infrastructure here, nothing here, nothing. It’s horrible when people just die at night.”

People were wounded in the city’s Sviatoshynskyi and Solomianskyi districts. Fires broke out in two other city districts as a result of falling debris from drones shot down by Ukrainian air defenses, the mayor said.

Moscow escalated attacks after Ukraine’s Security Service agency staged an audacious operation targeting warplanes in air bases deep inside Russian territory on June 1.

Illia Novikov in Kyiv, Ukraine, Jill Lawless and Rob Gillies in Kananaskis, Alberta, Brian Melley in London and Katie Marie Davies in Manchester, England, contributed.

Follow AP’s coverage of the war in Ukraine at https://apnews.com/hub/russia-ukraine