UN Secretary General Antonio Guterres has requested in writing to meet the leaders of Russia and Ukraine in their respective capitals.

Guterres asked Russian President Vladimir Putin to receive him in Moscow and Ukrainian President Volodymyr Zelenskyy to do so in Kyiv.

The UN chief's letters to this end were handed to the permanent missions of Russia and Ukraine in New York on Tuesday.

UN spokesperson Stephane Dujarric disclosed Guterres told both representatives of his hope to discuss urgent steps to bring about peace in Ukraine and the future of multilateralism based on the Charter of the United Nations and international law.

The development comes as Guterres has repeatedly expressed willingness to serve as a mediator to realize a ceasefire.

Also on Tuesday, Guterres called for a four-day humanitarian truce starting on Thursday that coincides with the Easter holidays observed by the Orthodox Church.