Kyiv vows to strengthen its armed forces after major Russian air strikes

Ukraine vowed to strengthen its armed forces after Russia launched its biggest aerial assaults on cities since the beginning of the war, forcing thousands to flee to bomb shelters, and prompting Kyiv to halt electricity exports to Europe.

Missiles hit targets across Ukraine on Monday morning, killing 14 people and injuring hundreds more, as they tore into intersections, parks, and tourist sites.

Explosions were reported in Kyiv, Lviv, Ternopil and Zhytomyr in western Ukraine, Dnipro and Kremenchuk in the centre, Zaporizhzhia in the south, and Kharkiv in the east, Ukrainian officials said.

The barrage of dozens of cruise missiles fired from air, land and sea was the most widespread wave of air strikes to hit away from the front line, at least since the initial volleys on the war's first day, February 24.

Russian President Vladimir Putin said he ordered "massive" long-range strikes, after accusing Ukraine of an attack on a bridge linking Russia to annexed Crimea on Saturday, but the United States said the scale of the attacks meant they had likely been planned for longer.

Ukrainian President Volodymyr Zelensky spoke to US President Joe Biden on Monday and wrote on Telegram afterwards that air defence was the "number 1 priority in our defence cooperation".

"We will do everything to strengthen our armed forces," he said in a Monday night address.

"We will make the battlefield more painful for the enemy."

Biden told Zelensky that the United States would provide advanced air defence systems. The Pentagon said on September 27 that it would start delivering the National Advanced Surface-to-Air Missile System (NASAMS) over the next two months or so.

A total of 14 people were killed and 97 were injured, the State Emergency Service of Ukraine reported. The rush-hour attacks were deliberately timed to kill people and knock out Ukraine's power grid, according to Zelensky.

Prime Minister Denys Shmyhal reported that 11 major infrastructure targets were hit in eight regions, leaving parts of Ukraine with no electricity, water or heat. He promised to restore utilities as quickly as possible.

As it tried to end blackouts, Ukraine halted electricity exports to the European Union (EU), at a time when the continent already faces surging power prices that have stoked inflation, hampered industrial activity and caused sky-high consumer bills.

Battlefield setbacks

The Kremlin's air strikes come three days after a blast damaged the bridge it built after seizing Crimea in 2014. Russia blamed Ukraine, and called the deadly explosion "terrorism".

"To leave such acts without a response is simply impossible," said Putin, alleging other, unspecified attacks on Russian energy infrastructure. He threatened more strikes in the future if Ukraine hit Russian territory again.

The United States, however, said attacks of such a scale could not have been put together in just a couple of days.

"It likely was something that they had been planning for quite some time," White House national security spokesperson John Kirby told CNN.

"That's not to say that the explosion on the Crimea bridge might have accelerated some of their planning."

Ukraine, which views the bridge as a military target sustaining Russia's war effort, celebrated the blast without claiming responsibility.

After weeks of setbacks on the battlefield, Russian authorities are facing the first sustained domestic criticism of the war, with commentators on state television demanding ever tougher measures.

Putin responded to Ukrainian advances by ordering the mobilisation of hundreds of thousands of reservists, proclaiming the annexation of occupied territory and threatening to use nuclear weapons.

Biden and the Group of Seven (G7) leaders will hold a virtual meeting on Tuesday to discuss their commitment to support Ukraine, the White House said.