The United Nations says Secretary-General Antonio Guterres will meet with Russia's President Vladimir Putin in Moscow on Tuesday and with Ukraine's President Volodymyr Zelenskyy in Kyiv two days later.

A UN spokesperson told reporters on Friday that while in Moscow, Guterres will have a meeting with Russian Foreign Minister Sergey Lavrov and will be received by Putin on Tuesday.

The spokesperson said the UN chief is hoping to discuss what can be done "in order to silence the guns, in order to help the people and in order to allow the people who need to get out and have safe passage."

The UN says Guterres will then travel to Ukraine and hold talks with Zelenskyy and Foreign Minister Dmytro Kuleba on Thursday.

Guterres has repeatedly urged Russia to exercise restraint, and has been calling on the sides to broker a ceasefire on humanitarian grounds to stop civilian casualties.