The prosecution of International Criminal Court judges in Russia is an attempt to "undermine the mandate" of the Hague-based court, which issued an arrest warrant for the Russian president, four countries said in a joint statement.

Costa Rica, Italy, Japan, and the United Kingdom — all of which are states parties to the International Criminal Court — issued a joint statement following the criminal procedure by Russian authorities against ICC prosecutor Karim Khan and its three judges.

"The Court represents the commitment of its states parties to ensure accountability for the most serious crimes of concern to the international community as a whole," the statement reads.

"It is regrettable that Russia continues its attempt to undermine the mandate of the Court, and we reiterate our unwavering commitment to stand firmly by the Court, its officials and personnel, as well as those cooperating with it, together with other states parties.

The four countries reaffirmed "full confidence in the Court as an independent and impartial court of law" and renewed their "resolve to defend the principles and values enshrined in the Rome Statute, preserving the Court’s integrity undeterred by any threats".

In March, the ICC issued an arrest warrant for Russian president Vladimir Putin and his children’s ombudsman, Maria Lvova-Belova, for complicity in the abduction of children from Ukraine.

Russia declared the Court’s decision ‘illegal’ and opened criminal proceedings against the court's prosecutor, Karim Khan, and its three judges.