Mr Ruto, who is accused of orchestrating a wave of violence after Kenya’s contested 2007 election, had asked judges to uphold an earlier ruling that he need only attend the opening and closing sessions of his trial in The Hague, as well as hearings at which victims aired their grievances.
“The absence of the accused can only take place in exceptional circumstances and must not become the rule,” said ICC president Song Sang-hyun. The ruling means Mr Ruto may still be able to stay away from court for much of his trial, but judges will need to authorise each absence.
Judges last week gave Kenyan President Uhuru Kenyatta blanket leave to be excused from attending his trial on similar charges. That decision looked set to defuse a row between the court and some African leaders who had been urging him to boycott the trial and who have charged the court with neo-colonial meddling.
Prosecutors have not yet appealed that decision, which would allow Kenyatta to attend to his presidential duties on an almost full-time basis even after his trial starts on November. 12. Friday’s ruling means any appeal they lodge would be more likely to succeed.
Many observers had expected judges to uphold the ruling that Ruto be excused from trial sessions after judges agreed to adjourn Mr Ruto’s trial to allow him to return home to deal with the aftermath of the militant raid on a Nairobi shopping mall that killed 67 people, including Kenyatta’s nephew.