Poland's prime minister says authorities have arrested a Russian citizen allegedly recruited by Russian secret services. The suspect reportedly planned to kill a Ukrainian American citizen in Warsaw. Polish Prime Minister Donald Tusk said it marks the first time Russia sought to attack an American citizen in another NATO country. Tusk says the victim was “uncomfortable for the Putin regime.” Polish authorities took the Russian citizen into custody on August 7. The operation was carried out with U.S. services, according to Poland's minister coordinating secret services. Officials have not provided more details about the case.