He is the second African leader to reveal that he has spoken to Mr Putin - the other is Egypt's President Abdul Fattah al-Sisi.

In a tweet, Mr Sall said: "As president of the African Union, I am delighted about my talk this morning with President Putin to press for a lasting ceasefire.

"I commend him for listening and for his willingness to maintain dialogue for a negotiated outcome to the conflict."

Mr Sisi's office said his talks with Mr Putin focused on the Ukraine crisis, and on strengthening relations between the two nations.

After Russian troops entered Ukraine on 24 February, the AU issued a statement calling for Ukraine's territorial integrity to be respected and for international law to be upheld.

The West African regional bloc Ecowas said it condemned the invasion.