Hundreds of thousands of Ukrainian civilians have fled the fighting since President Vladamir Putin ordered a full-scale invasion nearly a week ago.
Yet, Russia has failed to capture a single major Ukrainian city and Western analysts say Moscow appears to have fallen back on the devastating shelling of built-up areas before entering them.
A senior US defense official said on Tuesday the invading force's advance on Kyiv had stalled due to logistics problems, including shortages of food and fuel, and some units appeared to have low morale.
"While he may make gains on the battlefield – he will pay a continuing high price over the long run," US President Joe Biden said in his State of the Union address. Straying from the prepared text, Biden added "He has no idea what's coming."
US lawmakers stood and applauded, many waving Ukrainian flags, as Biden delivered his address to the chamber of the House of Representatives.
Ukrainian President Volodymyr Zelenskiy again called on Russia to stop bombarding civilians and resume talks.
"It's necessary to at least stop bombing people, just stop the bombing and then sit down at the negotiating table," he told Reuters and CNN in a joint interview in a heavily guarded government compound in Kyiv.
The United Nations General Assembly is set to vote on Wednesday on a resolution reprimanding Russia for invading Ukraine and demanding that it withdraw its military forces, a move that aims to diplomatically isolate Russia at the world body.
Russia's assault included strikes on Kyiv, though the heaviest bombardment so far appeared to be around Ukraine's second-largest city Kharkiv, near the border with Russia.
Dozens of residents there, including children, were killed when a Russian strategic bomber fired 16 guided missiles toward a residential area on Monday, Ukraine's defence ministry said.
West of Kyiv, in the city of Zhytomyr, four people, including a child, were killed by a Russian cruise missile, a Ukrainian official said.
In Ukraine's largely Russian-speaking city of Donetsk, in territory controlled by Russian-backed separatists, authorities said three civilians had been killed by Ukrainian shelling.
Vastly outmatched by Russia's military, in terms of raw numbers and firepower, Ukraine's own air force is still flying and its air defences are still deemed to be viable - a fact that is baffling military experts.
Biden announced a further ratcheting up of sanctions on Moscow, joining the European Union and Canada in banning Russian planes from US airspace. He also said the Justice Department would seek to seize the yachts, luxury apartments and private jets of wealthy Russians with ties to Putin.
Ukraine has called on the US-led military alliance to implement a no-fly zone over Ukraine - a request rejected by Washington, which fears stoking a direct conflict between the world's two biggest nuclear powers.
Washington and its allies have instead sent weapons to Kyiv.
The West's main strategy is shutting off Russia's economy from the global financial system, pushing international companies to halt sales, cut ties, and dump tens of billions of dollars' worth of investments.
Exxon Mobil joined other major Western energy companies including British BP PLC and Shell in announcing it would quit oil-rich Russia over the invasion.
Apple Inc stopped sales of iPhones and other products in Russia, and was making changes to its Maps app to protect civilians in Ukraine. Alphabet Inc's Google dropped Russian state publishers from its news, and Ford Motor suspended operations in the country.
US airplane manufacturer Boeing said it was suspending parts, maintenance and technical support for Russian airlines.
Russia on Tuesday placed temporary restrictions on foreigners seeking to exit Russia assets, meaning that billions of dollars worth of securities held by foreigners are at risk of being trapped.
16°C