The International Criminal Court's chief prosecutor said Sudan had promised its "full cooperation" in the war crimes probe of atrocities committed in the Darfur region under ousted president Omar al-Bashir.
Karim Khan spoke after meeting army chief Abdel Fattah al-Burhan -- who seized power last year in a coup.
"The words that I have just heard from the chair of the sovereignty council are very positive. The challenge now is delivering those in practice. What I do say is that we need to act. It is an embarrassment, a collective embarrassment that after 17 years of the Security Council referral, so much more still needs to be done," he said.
Burhan, who was a senior general under Bashir, has promised his "full cooperation" and commitment to "justice for the people in Darfur", Khan added, as he wrapped up his trip.
"Unless we collectively can find some system of accountability, which is seen to be independent, credible, impartial and not trying to hide the truth but is willing to speak the truth, I think the cycle of violence that we saw in 2003 and (2004) commence," Karim Khan added.
Bashir, 78, who has been in custody in Khartoum since his 2019 ouster, has been wanted by the ICC for more than a decade over charges of genocide, war crimes and crimes against humanity in Darfur.
Two other former aides are also wanted by The Hague-based court to face war crimes charges.