The United Nations says Secretary-General Antonio Guterres met with Sudan's president, who is accused of genocide by the International Criminal Court, on the sidelines of the African Union summit on grounds of "operational necessity."

U.N. deputy spokesman Farhan Haq told reporters Monday that those grounds allow the U.N. chief to meet with President Omar al-Bashir "from time to time" on issues such as the U.N. peacekeeping missions in Darfur and the oil-rich Abyei border region that is disputed between Sudan and South Sudan.

Sudanese Foreign Minister Ibrahim Ghandour told local media that Guterres praised efforts by Sudan's government to achieve peace in Darfur, Blue Nile and South Kordofan while meeting in Addis Ababa.

Al-Bashir is accused of genocide, crimes against humanity and war crimes in Darfur during fighting since 2003.