UNITED NATIONS, United States (AFP) - Ukrainian President Volodymyr Zelensky will speak on Tuesday (April 5) during a United Nations Security Council meeting on the conflict in his country, Britain's diplomatic mission announced, the leader's first address to a UN body since Russia invaded on Feb 24.

Following the Monday announcement, Britain - which holds the council presidency for April - was unable to say if the speech would be live or recorded in advance.

The Ukrainian leader has already spoken by video link to more than a dozen assemblies – including the US Congress, the British parliament and the European Parliament.

Tuesday's session was already on the calendar before the announcement of Zelensky's appearance, and will include the participation of UN Secretary-General Antonio Guterres.

The meeting will now likely be dominated by the weekend discovery of dead bodies in civilian clothing scattered on the streets of Bucha, a town outside Kyiv. Photos of the horrific scene have drawn international condemnation of Russia.

On Monday, Zelensky, wearing a khaki coat and camouflage body armour, spent half an hour in the suburb of Bucha. He blamed Russian troops for the killings.

"These are war crimes and it will be recognised by the world as genocide," he said.

Russia has denied responsibility and suggested images of corpses were "fakes". "The UK presidency of the Council will ensure the truth is heard about Russia's war crimes. We will expose Putin's war for what it really is," Britain's UN mission said on its official Twitter account.