
Russian forces are consolidating in southern and eastern Ukraine
Here's your 10-point cheatsheet to this big story:
Mr Zelensky is expected to discuss the grisly discovery of dozens of bodies in Bucha and other towns around Kyiv, from which Russian forces have withdrawn. During a visit to Bucha on Monday, he accused Russia of "genocide".
US President Joe Biden has called for a war crimes trial and more sanctions on Russia over the deaths in Bucha.
The European Union offered to send a team of investigators to Ukraine gather evidence. The EU said it is discussing new punitive measures against Moscow. A top official said the EU is considering sanctions on Russian oil and coal.
Moscow denied responsibility for civilian deaths, claiming images of dead bodies in Bucha and other Kyiv suburbs are "fakes".
The Russian Defence Ministry accused the Ukrainian military of staging civilian deaths in a video it claimed was made on Monday in the village of Motyzhyn, but provided no proof of its claims.
Ukrainian authorities said they found the bodies of five civilians with their hands tied in Motyzhyn, including those of the mayor, her husband and son. Police showed four bodies, including that of the mayor, half-buried in a grave in a forest near her house and a fifth body in a nearby well.
The Red Cross said a team that was detained on its way to help evacuate civilians from the besieged port city of Mariupol on Monday has been released. The workers were detained in the town of Mangush, which is under Russian control.
Russian troops are gearing up for a big attack in the Lugansk region of eastern Ukraine, the local governor Sergiy Gaiday said on Telegram. "We see that equipment is coming from different directions, they are bringing manpower, they are bringing fuel," he said.
Denmark said it is expelling 15 Russian diplomats for spying, a day after Germany and France also ordered dozens of Russian diplomats home. The former Soviet republic of Lithuania also expelled the Russian ambassador to Vilnius over what it calls the "horrific massacre" in Bucha and atrocities in other cities.
More than 4.2 million Ukrainian refugees have fled the country since the Russian invasion, the UN said.