Ukrainian defenders battled to contain Russian forces along several fronts, officials said, as the US urged China to align itself with the West in opposing the invasion following an ill-tempered G20 meeting.
A missile strike on the northeastern city of Kharkiv wounded three civilians, its governor said, though Russia's main attacks appeared focused southeast of there in Luhansk and Donetsk.
Those two provinces, swathes of which were held by pro-Russian separatists before the conflict began in February, comprise the eastern industrial region of the Donbas.
Ukrainian officials reported strikes in both today, while Britain's Ministry of Defence said Moscow was assembling reserve forces from across Russia near Ukraine.
Donetsk regional Governor Pavlo Kyrylenko said on the Telegram messaging service that a Russian missile had struck Druzhkivka, a town behind the front line, and reported shelling of other population centres.
Luhansk Governor Serhiy Gaidai said on Telegram that Russian forces were "firing along the entire front line", though a subsequent Ukrainian counter-attack that hit weapons and ammunition stores had forced Moscow to halt its offensive.
Russia, which claimed control over all of Luhansk province last weekend, denies targeting civilians.
On Friday, Ukraine had pleaded for more of the high-end weapons from the West that Kyiv said had enabled it to slow Russia's advance.
Hours later, US President Joe Biden signed a weapons package for Ukraine worth up €$400 million, including four additional high mobility artillery rocket systems.
Ukrainian President Volodymyr Zelensky said the armaments were priority needs. "It is what helps us press on the enemy," he said on Twitter.
In reaction, the Russian embassy in Washington said the US wanted to "prolong the conflict at all costs".
China-US relations
Earlier, US Secretary of State Antony Blinken, urging the international community to join forces to condemn Russian aggression, told journalists he had raised concerns with his Chinese counterpart Wang Yi over Beijing's alignment with Moscow.
The pair held over five hours of talks on the sidelines of the G20 gathering of foreign ministers on the Indonesian island of Bali.
Yesterday, Russia's Sergei Lavrov had walked out of a meeting there, denouncing the West for its "frenzied criticism".
The Chinese foreign ministry said, without giving details, that Mr Wang and Mr Blinken had exchanged views on "the Ukraine issue".
It also quoted Mr Wang as saying that Sino-American relations were in danger of being further led "astray", with many people believing that "the United States is suffering from an increasingly serious bout of 'Chinaphobia'."
Shortly before the Russian invasion, Beijing and Moscow announced a "no limits" partnership, although US officials have said they have not seen China evade US-led sanctions on Russia or provide it with military equipment.
Kharkiv's Governor Oleh Synehubov said on Telegram that, as well as the missile strike, fighters had repulsed two Russian attacks near Dementiivka, a town situated between the city and the border with Russia.
Russia's defence ministry said its forces hit two "bases of foreign mercenaries deployed near Kharkiv".
Ministry spokesperson Igor Konashenkov also said two Ukrainian Su-25 aircraft had been shot down in the southern Mykolaiv region, and that it had destroyed ammunition depots there and in the eastern regions of Dnipropetrovsk and Donetsk.
Russian-backed forces on the territory of the self-proclaimed Donetsk People's Republic (DPR) said three people died and 17 were wounded there in the past 24 hours as Ukrainian forces shelled 10 locations.
Battlefield accounts could not be independently verified.
Ukraine calls for more sanctions
Following Friday's testy G20 exchanges, Russian President Vladimir Putin also signalled that the Kremlin was in no mood for compromise, saying sanctions against Russia risked causing "catastrophic" energy price rises.
Ukraine's Foreign Minister Dmytro Kuleba said that sanctions were working, and echoed calls for more deliveries of high-precision Western weapons.
"Russians desperately try to lift those sanctions which proves that they do hurt them. Therefore, sanctions must be stepped up until Putin drops his aggressive plans," Mr Kuleba told a forum in Dubrovnik by videolink.
Russia's ambassador to Britain, Andrei Kelin offered little prospect of a pullback from parts of Ukraine under Russian control and said Russian troops would capture the rest of Donbas.
Since Russia, which has also seized a big chunk of territory across Ukraine's south, started what it calls a special operation to demilitarize Ukraine, cities have been bombed to rubble, thousands have been killed, and millions displaced.
Ukraine and its Western allies say Russia is engaged in an unprovoked land grab.
