Russia said it will repeat its request for the United Nations Security Council to meet on Monday over what Moscow described as "criminal provocations by Ukrainian soldiers and radicals" in the Ukrainian city of Bucha.

The United Kingdom's mission to the U.N., which assumed the presidency of the 15-member Security Council for April, has said the group will hold a scheduled discussion on Ukraine on Tuesday, rather than meet on Monday as requested by Russia.

"Yesterday, in the worst English tradition, the British presidency of the U.N. Security Council did not give consent to holding a meeting of the Security Council on the situation in Bucha," Russian Ministry of Foreign Affairs spokeswoman Maria Zakharova said in a statement via Telegram on Monday. "Russia today will again demand the convening of the U.N. Security Council in connection with the criminal provocations of the Ukrainian military and radicals in this city."

Ukrainian Prosecutor General Iryna Venedyktova announced Sunday that 410 civilians were found dead in recently recaptured towns near the capital as part of an investigation into possible war crimes by Russian forces. Images emerged showing bodies in civilian clothes strewn in the streets of Bucha, northwest of Kyiv.

Russia's deputy representative to the U.N. Security Council, Dmitry Polyansky, said via Twitter on Sunday that Moscow had requested a meeting to be held on Monday "in connection with the monstrous provocation of Ukrainian radicals in Bucha."

Russian forces are continuing to consolidate and reorganize as they refocus their offensive into the Donbas region of eastern Ukraine, the U.K. Ministry of Defense said in an intelligence update Monday.

"Russian troops, including mercenaries from the Russian state-linked Wagner private military company, are being moved into the area," the ministry added.

Wagner is the best-known of an array of Russian mercenary groups and has ties to Russian President Vladimir Putin. The Russian company has deployed fighters to countries in the Middle East and Africa. U.S. Department of Defense spokesperson John Kirby told reporters last month that Wagner "has an interest in increasing their footprint in Ukraine."

Ukrainian President Volodymyr Zelenskyy made a brief speech at the 2022 Grammy Awards on Sunday night.

Zelenskyy, in a video message, said war is the opposite of music, but hopes soon the silence of death will be filled with the sound of music.

"The war doesn't let us choose who survives and who stays in eternal silence. Our musicians wear body armor instead of tuxedos," Zelenskyy told the audience. "They sing to the wounded. In hospitals. Even to those who can't hear them. But the music will break through anyway."

At least seven civilians are dead and 34 are wounded following shelling in Kharkiv, the region's prosecutor's office announced Sunday.

The shelling occurred Sunday evening in the city's Slobidskyi district, according to the Kharkiv regional military administration Oleg Sinehubov, who added that children are among the victims.

Meanwhile, in Chernihiv, around 70% of the city has been destroyed, according to Mayor Vladyslav Atroshenko, who was speaking on Ukrainian TV.

He added that businesses are not operating. Ukrainian soldiers have been able to liberate several villages in the Chernihiv region in the past couple of days.

-ABC News' Christine Theodorou

All Russian troops have left the Ukrainian cities of Kyiv and Chernihiv, withdrawing north toward the borders of Belarus and Russia to consolidate before likely redeploying to the Donbas region in eastern Ukraine, a senior U.S. defense official told reporters Wednesday.

But even with the Russians gone, the territory remains treacherous.

"There are some indications that they left behind mines and things like that, so the Ukrainians are being somewhat careful in some areas north of Kyiv as they begin to clear the ground and clear the territory and re-occupy it," the official said.

While the U.S. hasn't yet seen these troops redeploy elsewhere in Ukraine, it'll likely happen soon, according to the official. Ukrainian forces are preparing for a major fight in Donbas, the official said.

The official also said the Pentagon is "monitoring" an apparent nitric acid explosion in Ukraine's Luhansk region, which Russia blamed on Ukraine.

"We've seen the Russians claim that this was a Ukrainian attack on this. We do not believe that is true," the official said. "We do believe that the Russians are responsible, but exactly what they used when they did it, why they did it, what the damage is, we just don't have that level of detail," the official said.

The official also noted that a small number of Ukrainians currently in the U.S. for "professional military education" were pulled aside for a couple days of training on Switchblade drones, which the U.S. is sending overseas as part of its military aid, according to the official.

"Although it's not a very difficult system to operate, we took advantage of having them in the country to give them some rudimentary training on that," the official said.

-ABC News' Matt Seyler