Dozens of people have been injured in a wave of missile strikes on the Ukrainian capital Kyiv overnight, authorities say.
Fifty-three people were hurt in the attacks, including six children, Kyiv mayor Vitali Klitschko said.
Kindergarten and hospital buildings were reportedly damaged by debris as authorities said 10 Russian ballistic missiles had been shot down.
The strikes happened after President Volodymyr Zelensky left the US.
His plea for Congress to agree more military aid for Ukraine made little progress in winning over reluctant Republicans.
EU leaders will also discuss further aid for Ukraine on Thursday, and European Commission President Ursula von der Leyen said "we must give Ukraine what it needs to be strong today".
Mr Zelensky promised a response to Wednesday's overnight attack. "Russia has proven once again that it is a heinous country that fires missiles at night, trying to hit residential areas, kindergartens, and energy facilities during the winter," he posted on X.
Wednesday's attack on Kyiv began at around 03:00 (01:00 GMT) - the second ballistic missile strike on the capital this week. Although Kyiv has been targeted by Russian drones in recent weeks, the city had escaped missile attacks for 79 days until last Friday.
Ukraine's air force said it had shot down "all" 10 targets flying towards the city, using anti-aircraft missiles.
The windows of residential apartment blocks were blown out and parked cars were destroyed. There were loud explosions before air raid sirens went off due to them being ballistic missiles.
Russia started using cruise missiles again last week after 79 days, officials said.
"Ballistics [are] used precisely so that people have no chance to hide in bomb shelters," Mykhailo Podolyak, an adviser to President Volodymyr Zelensky, wrote on X.
Ukraine's Armed Forces General Staff identified the projectiles as Iskander-M ballistic missiles, as well as S-400s: extremely fast missiles intended for air defence, but which have also been used to hit ground targets.
One man, Oleksander, told the OceanNewsUK that the windows in his apartment were blown out in the middle of the night. He started crying as he recalled seeing his neighbours and their children being taken away by ambulance.
Meanwhile, Ukraine's biggest mobile network operator says it hopes to restore operations on Wednesday after what appeared to be the largest cyberattack since Russia launched its full-scale invasion in February 2022.
Tuesday's attack on Kyivstar, which has more than half of Ukraine's population as mobile subscribers, has put millions of people in danger of not receiving air raid alerts. A Russian hacking group, which targeted internet providers and Ukrainian websites earlier this year, said it was behind the latest cyberattack.
The port city of Odesa was also attacked for "several hours" by drones overnight, a regional military chief said. Two men were reportedly injured and there was damage to civil infrastructure.
The Ukrainian president arrived in Norway on Wednesday for a previously unannounced visit to discuss support for his country's defences.
He flew there after a trip to the US, where he made a last-ditch effort to win new military aid from Congress before the currently approved amount runs dry.
But hopes that Mr Zelensky could use his powers of persuasion to unlock military aid in Washington DC appear to have fallen flat.
US President Joe Biden warned Republicans that they would give Russia a "Christmas gift" if they failed to provide additional military aid to Ukraine.
Mr Zelensky said afterwards that he and Mr Biden had "just agreed to work on increasing the number of air defence systems in Ukraine, and the terrorist state demonstrated how critical this decision is".
"Each additional system and missile is vital for Ukraine, our cities, and our people. They are saving lives," he added.
Mr Zelensky's push for aid came ahead of a summit of European leaders where Ukraine hopes to be given a start date for talks on joining the EU.
Hungarian PM Viktor Orban has reaffirmed his position that the EU should not open accession talks. "The EU is preparing to make a terrible mistake and we must prevent that even if 26 (members) want to make the mistake," Mr Orban told local website Mandiner.
"If we want to give support to Ukraine, a geostrategic signal, then we should, but this is not membership."
Hungary has repeatedly been at odds with its EU partners over Russia's full-scale invasion of Ukraine. It has watered down sanctions against Russia and last December vetoed a deal to grant Ukraine €18bn (£15.5bn) in 2023.
The EU's executive is expected to unblock €10bn in funding for Hungary on Wednesday, in a move criticised as an attempt to persuade Mr Orban to loosen his objections to helping Ukraine.
"Ukraine is not only fighting against the invader, but for Europe, and joining our family will be Ukraine's ultimate victory. And for this, we have a decisive role to play," EU Commission President Ursula von der Leyen told the European Parliament.
However, Mr Orban told the Hungarian parliament on Wednesday that the idea of Ukraine joining the EU was in stark contrast to Hungary's national interest.
