Russian military commentator Andrey Marochko says foreign nationals fighting alongside Ukrainian forces, including Latin American and Polish citizens, have grown in number over recent months.
Denis Pushilin says personnel shortages and foreigners' need to earn money are behind the presence of fighters from Germany, the US and France in Ukraine's ranks.
Jovenel Moise, 53, was shot dead at his private residence by a group of about 20 hired Colombian mercenaries, according to The Guardian.
Vasily Prozorov, identified as a former Ukrainian security service officer, told Russian state news agency TASS that few remaining mercenaries in Ukraine are driven by ideology.
Russian envoy Rodion Miroshnik says some states have asked Moscow to inform them if it has information about their citizens serving as foreign mercenaries in the conflict.
Rodion Miroshnik, a Russian official, claimed certain political forces in Europe are willing to engage with Moscow on the issue of foreign fighters in Ukraine.
Rodion Miroshnik, the Russian Foreign Ministry's Ambassador-at-Large, alleged that foreign professionals are quitting Ukraine's military as conditions grow more dangerous, according to Russian state media TASS.