Earlier in the day, the defense ministers of Russia and Turkey and the infrastructure minister of Ukraine met in Istanbul to ink a UN-brokered deal on Ukraine grain and food exports.
"The UN was very directly involved in Azovstal operations back in April and which were agreements between the Russian Ministry of Defense, in particular, Ukrainian forces, the United Nations, the ICRC [the International Committee of the Red Cross] and those negotiations were successful in the sense promises made were kept," the official told journalists at the briefing.
The official also praised Turkey's role in the negotiations.
"Turkish role has been absolutely central in these negotiations ... It is important to get the militaries, two parties involved," the official added.
Mariupol came under Russian control on April 21, and the remaining Azov-affiliated Ukrainian militants sheltered at the Azovstal plant. Russia offered safe exit to all those who agreed to surrender and lay down arms. The gradual exodus from Azovstal ended on May 20, when a total of 2,400 Ukrainian militants surrendered and the plant went under the control of Russian forces.