Russia and Ukraine agreed to open more humanitarian corridors on Wednesday to evacuate terrified civilians from bombarded cities, while new concerns emerged over the Chernobyl nuclear plant after a power cut.
As fighting raged on the 14th day of the invasion, safe routes were opening out of five Ukrainian areas including suburbs of the capital Kyiv that have been devastated by Russian shelling and air strikes.
Russian troops were seen by AFP Wednesday pushing closer to the capital Kyiv, while Moscow accused the United States of waging "economic war" through a barrage of sanctions.
With Ukrainian cities still being pummelled, President Volodmyr Zelenskiy urged Western powers to decide on a Polish offer to supply his country with fighter jets, after Washington rejected an initial plan.
"We ask you again to decide as soon as possible. Send us planes," he said.
Russia's war has sent around 2.2 million refugees across Ukraine's borders in what the UN has called Europe's fastest-growing refugee crisis since World War II, and sparked fears of wider conflict.
Fears are mounting that Russia will encircle Kyiv, where an orchestra performed in the city's famous Maidan Square in a morale-boosting concert that included the EU anthem "Ode to Joy."
'Columns of Russian tanks'
Moscow had vowed to respect a 12-hour truce starting at 9:00 am to allow civilians to flee six areas that have been heavily hit by fighting, Ukrainian Deputy Prime Minister Iryna Vereshchuk said.
For the first time the corridors included Irpin, Bucha and Gostomel, a cluster of towns on the northwestern outskirts of Kyiv that have been largely occupied by Russian forces.
Another evacuation route is from Sumy, where some 5,000 civilians were able to escape on Tuesday as some 60 buses left the stricken town east of Kyiv near the Russian border.
Vereshchuk said Ukraine has had a "negative experience" of ceasefires not being respected, adding that residents had asked Russia to "keep its promises."
But Russian forces had made rapid advances towards Kyiv, approaching Brovary, the large eastern suburbs of the capital, AFP journalists saw.
"The columns of Russian tanks yesterday took two villages a few kilometers away," Volodymyr, a 41-year-old resident of Velyka Dymerka, about 15 kilometers (nine miles) from Brovary.
"They shoot to scare people and force them to stay at home, steal what they can to get supplies and settle among the inhabitants, so that the Ukrainian forces do not bomb them."
While the front line was five days ago near Chernihiv, about 100 kilometers north of Brovary, columns of Russian tanks were only about 15 km away on Wednesday, according to the AFP journalists who could hear the fighting a few kilometers away.
Fighting later redoubled in the area, with Ukrainian forces trying to repel a column of Russian tanks which was heading towards the highway in the direction of Brovary, local residents and volunteers of the Ukrainian forces told AFP.
Chernobyl 'fully disconnected'
A corridor was also agreed for the port town of Mariupol, where several previous evacuations have failed, leaving thousands of people without water or power since Friday in what the International Committee of the Red Cross (ICRC) called "really apocalyptic."
Violence raged in other areas, with at least 10 people killed in a Russian military attack on homes and other buildings in the eastern Ukrainian town of Severodonestk on Tuesday, a local official for the Lugansk region said in a statement on Telegram.
The invasion has also raised nuclear concerns, with Ukraine saying on Wednesday that power has been cut to Chernobyl, site of the world's worst nuclear disaster in 1986, which has been seized by Russian forces.
The defunct plant, housing decommissioned reactors and radioactive waste facilities seized by Russia at the start of the war, "was fully disconnected from the power grid," Ukraine's energy operator Ukrenergo said.
The UN atomic watchdog, the International Atomic Energy Agency (IAEA) said that while the development violated a "key safety pillar," it saw "no critical impact on safety" at Chernobyl.
Russia also attacked and seized Europe's largest atomic power plant, Zaporizhzhia, last week, drawing accusations of "nuclear terror" from Kyiv.
'Economic war on Russia'
Western allies have hit Russia with unprecedented sanctions, with the United States on Tuesday announcing sanctions on the oil imports that help bankroll Moscow's war machine.
The spike in energy prices caused by Russia's war in Ukraine will produce effects comparable to the 1973 oil shock, French Economy Minister Bruno Le Maire warned on Wednesday.
The EU on Wednesday agreed to add more Russian oligarchs to the sanctions blacklist, and to cut three Belarusian banks from the global SWIFT payments system over Minsk's support for the Kremlin's attack.
A corporate boycott grew too, with Dutch brewery Heineken and Universal Music joining McDonald's, Coca-Cola and Starbucks among the big brands to suspend business in Russia.
The Kremlin, scrambling to impose measures to limit the economic fallout, hit back by accusing the United States of having "declared economic war on Russia."
But Russian Foreign Ministry spokeswoman Maria Zakharova said that "some progress has been made" in three rounds of negotiations with officials from Kyiv, adding that Moscow's troops were not trying to "overthrow" the Ukrainian government.
Russian President Vladimir Putin has vowed the "neutralization" and "denazification" of pro-Western Ukraine, and raised Russia's nuclear alert.
Western governments have baulked at the Ukranian president's calls for a no-fly zone to defend Ukraine's skies, fearing it would trigger a conflict with nuclear-armed Russia.
U.S. Vice President Kamala Harris was travelling to Poland on Wednesday after the Pentagon rejected the "not tenable" Polish plan to deliver MiG-29 fighter jets to a U.S. air base in Germany.
"The prospect of fighter jets... departing from a U.S./NATO base in Germany to fly into airspace that is contested with Russia over Ukraine raises serious concerns for the entire NATO alliance," spokesman John Kirby said.
The West has instead relied on funnelling weapons and aid into Ukraine.
British Defense Minister Ben Wallace said Wednesday that his country had delivered 3,615 NLAW anti-tank weapons, and would shortly start shipping a "small consignment" of Javelin anti-tank missiles.