He announced this at a briefing in Kyiv, Censor.NET reports.
"This step is conditioned by the fact that the current leadership of the prosecutor's office has completely turned it into a body where corruption and cover-up reign, and any attempt to change this state of affairs is immediately and demonstratively persecuted. The rule of law is out of here, while arbitrariness and lawlessness prevail. Each day, more key positions at the PGO are taken by followers of the infamous Viktor Pshonka [fugitive Yanukovych-era prosecutor general - ed.]," Kasko remarked.
He stressed that the allegedly reformed body covers up the same political patronage, direct and total pressure on investigators and prosecutors, deliberate and professional degradation, inaction and impunity.
"Under the current leadership, the law enforcement authority meant to fairly and transparently investigate corruption and other crimes of Yanukovych after the Revolution of Dignity has completely turned into a tool of political intimidation and dirty gains.
"I can not and do not want to be part of the body that encourages total lawlessness instead of protecting the law. Ukraine pays quite a price for cleansing of corrupt politicians, venal law enforcers, and kleptocrats that have united and become a single decision-making center in the country," Kasko said.
He also added that with the current PGO leadership he no longer sees any opportunities to "help create a truly European prosecutor's office in Ukraine."
"Therefore, I see no reason to stay," Kasko summed up.