Russia launched a wide drone and missile attack across Ukraine on Wednesday, killing at least five people, Ukrainian officials said.
The attack comes a day after US President Donald Trump put his planned meeting with Russian leader Vladimir Putin on hold, saying he did not want it to be a "waste of time".
Ukraine's energy minister said a "massive combined overnight attack" on Ukraine's energy infrastructure was still under way early on Wednesday -- the latest in Russia's effort to cripple the country's energy system before winter.
"As soon as security conditions allow, energy workers will begin assessing the consequences of the attack and carrying out repair work," the minister, Svitlana Hrynchuk, said in a statement.
In the Kyiv region, rescuers discovered the bodies of three people -- including two children -- after a strike set a private house on fire in the village of Pohreby, regional governor Mykola Kalashnyk said.
According to Mr Kalashnyk, the victims were a woman and her two daughters -- an infant of six months and a 12-year-old girl.
"Their bodies were found at the site of the fire," the governor said.
"This is a tragedy for the entire community, for the Kyiv region, and for the country."
Two more people were found dead in the Dnipro district of the Ukrainian capital, where emergency services rescued 10 people after a fire caused by drone debris hit the sixth floor of a 16-storey residential building, local authorities said.
The attack also blew out windows of a medical facility and debris was found at another residential building, Kyiv mayor Vitali Klitschko reported on his Telegram channel.
In the Darnytskyi district of the capital, emergency services were responding after drone debris hit a 17-storey residential building causing a fire on five floors. Fifteen people were rescued, including two children.
In the Desnianskyi district, 20 people were rescued after the façade of a 10-storey building was damaged and a gas pipe caught fire. Debris from a drone also fell on a dormitory building and rescue workers were headed to the scene, Mr Klitschko said.
The large-scale overnight aerial attack also targeted other cities in Ukraine including Zaporizhzhia and the port city of Izmail in the southern Odesa region.
Mr Trump was expected to hold talks at the White House on Wednesday with Nato secretary-general Mark Rutte.
The military alliance has been co-ordinating deliveries of weapons to Ukraine, many of them purchased from the US by Canada and European countries.
The decision to postpone the meeting in Budapest, Hungary -- which Mr Trump had announced last week -- followed a call on Monday between US secretary of state Marco Rubio and Russian foreign minister Sergey Lavrov.
The Russian diplomat made clear in public remarks on Tuesday that Moscow opposes an immediate ceasefire.
Meanwhile, Ukraine is seeking to purchase 25 Patriot air defence systems from US firms using frozen Russian assets and assistance from partners.
The country's president Volodymyr Zelensky said acquiring them would take time because of a long production lead-in but added that he had spoken to Mr Trump about help procuring them more quickly, potentially from European partners.
Earlier this month, Russia carried out its largest attack of the war on natural gas facilities operated by Ukraine's state-owned Naftogaz Group, launching 381 drones and 35 missiles, according to Ukraine's air force.
Officials said the strikes were part of an effort to cripple the country's power grid ahead of winter.