Ukraine's president said he discussed air defence assistance with US President Biden on Monday night, following Russia's massive bombing of several Ukrainian cities.
There's been international condemnation of Russia after Vladimir Putin ordered a wave of missile strikes across Ukraine on Monday morning, including against the capital Kyiv.
The strikes, the biggest and most widespread Russian attacks in months, are being seen as a major escalation by Moscow after a period of successful Ukrainian counteroffensives.
See a summary of Monday's developments in our blog below: