In a statement carried by the Croat-Muslim entity's news agency FENA, Masovic said the explanation of del Ponte's likely nonattendance, which she gave before the OSCE Permanent Council in Vienna last week, was unacceptable.
He said failure to attend would also represent an attempt by the chief prosecutor to run away from personal responsibility for the fact that the most wanted war criminals were still at large.
According to Masovic, one could not simply shift the responsibility for failure to arrest the fugitives on NATO troops or amnesty the UN court and its Prosecution.
"If (the Hague tribunal) think they have done everything in their power but have failed, it would be fair and moral of them to resign," Masovic said. He also condemned what he labelled del Ponte's ultimatum to the international community to arrest suspects or what he labelled her threat to reveal why they had not been arrested.
"She should first resign and then state her reasons," said Masovic.