Members of the Kenyan Parliament approved a measure this week to stop working with the international court.
The court scheduled a trial next week for Vice President William Ruto and national broadcast director Joshua Arap Sang. Both men, along with President Uhuru Kenyatta, are suspected of committing crimes against humanity during post-election conflicts in 2007. At least 1,000 Kenyans were killed during the violence.
Tiina Intelmann, president of the assembly of state parties to the Rome Statute of the ICC, said Friday she hoped Kenya would remain within the treaty that created the court.
"I hope that Kenya will remain within the Rome Statute and thus continue to contribute to the fight against impunity, which is a common endeavor of all states," she said in a statement from Uganda.
The final decision on the ICC rests with the Kenyatta. His trial is scheduled to begin Nov. 12.
Kenyan lawmakers said they were following the example of China, the United States and other world powers not party to the international criminal court. Intelmann reminded Nairobi, however, that leaving the court takes a year to go into force and has no bearing on cases already on its books.
ICC spokesman Fadi el-Abdallah said in a Thursday interview with the BBC the court "may decide to issue arrest warrants against these accused" if they failed to cooperate.