Ukraine's National Police have assembled evidence implicating hundreds of foreign mercenaries in illegal armed groups fighting for Russia, the force's investigative chief told a visiting FBI delegation on 4 June.
Maksym Tsutskiridze, first deputy head of the National Police and head of its Main Investigation Department, said his officers have documented the men's participation in illegal armed formations, a prosecutable offense under Ukrainian law. One suspect was detained in the United States while trying to cross the border from Mexico. Effective prosecution, he added, depends on rapid information exchange and coordinated analysis with foreign partners.
Hundreds identified amid a wider recruitment drive
The files form part of a broader push to hold non-Russian nationals accountable for fighting alongside Moscow's forces. Ukraine's foreign ministry reported that 2,965 citizens of 36 African countries had joined the invasion army as of May 2026. Military intelligence has separately verified the names of more than 1,000 Cuban recruits, while cautioning the real total could approach 15,000.
Mercenaries enjoy no combatant immunity under international law, which leaves them exposed to prosecution simply for taking part in hostilities, the legal basis Ukrainian investigators are using to pursue cases against them.
Cyber cooperation yields cases worth millions
National Police chief Ivan Vyhivskyi described the partnership with US law enforcement as practical and results-driven, pointing to joint operations against ransomware networks that struck companies across the United States and Europe. One investigation logged victim losses exceeding $120 million. In another, police identified 21 members of a criminal network behind attacks on American and European firms and traced more than $25 million in illicit proceeds.
So far in 2026, Ukraine has extradited two wanted individuals to the United States and secured the return of three citizens sought internationally, Vyhivskyi said. He added that Ukraine has become a leading source of intelligence on Russian-speaking transnational cyber groups targeting partners in the US, the European Union, and beyond.
FBI praises wartime expertise
Jason Foy Bilnoski, the FBI's deputy assistant director for cyber operations, credited Ukrainian officers with rare experience countering cyber threats during a full-scale war and called that knowledge valuable to law enforcement worldwide. The bureau wants to expand work on cybercrime, critical-infrastructure protection, and dismantling transnational criminal networks, he said.
The talks also covered war crimes investigations, narcotics trafficking, human trafficking, and money laundering. Both delegations confirmed their readiness to broaden cooperation.
