A senior U.S. envoy expressed strong concern Thursday about the activities of the Russian private military contractor Wagner Group and its alleged attempts to recruit soldiers in Serbia and elsewhere in the world.

U.S. State Department Counselor Derek Chollet said he voiced these concerns during talks in Belgrade with Serbian President Aleksandar Vucic.

“We have seen that the Wagner Group is seeking to recruit soldiers from Serbia and elsewhere, and that’s something we think cannot stand,” he told reporters after the meeting.

“I don’t know if there are concerns [in Serbia], we talked about our concerns and we are looking forward to working with the government here in Belgrade and elsewhere where Wagner is active to put an end to their activities,” he added.

Wagner Group, owned by Russian oligarch Yevgeny Prigozhin, reportedly has been active in dozens of mostly African states, working with governments on pro-Russian propaganda and other military and political projects.

The group has boasted about its presence in Serbia, the only European state besides Belarus that has not joined international sanctions against Russia for its war against Ukraine. The group has reportedly announced the opening of its offices in Belgrade, something that was later denied.

Moscow’s propaganda portal RT, which recently started its Serbian-language online news site in Serbia, has published Wagner’s recruitment advertisement seeking fighters in Ukraine, saying the group offers “more than attractive” incentives.

Chollet said Wagner Group is “in action in terrible ways throughout the world, whether it is in Libya, the Central African Republic or right now in Ukraine.”

The group, which reportedly includes a large contingent of convicts recruited in Russian prisons, has spearheaded the attacks in eastern Ukraine, including the fierce battles in Soledar and Bakhmut.

Prigozhin and his group have been under U.S. sanctions for years, and the U.S. has recently taken additional steps to try to control Wagner’s access to weapons.

Wagner Group mercenaries have also been accused by Western countries and United Nations experts of numerous human rights abuses throughout Africa, including in the Central African Republic, Libya and Mali. Earlier this month U.S. Secretary of State Antony Blinken announced he has designated the Wagner Group as an “entity of particular concern” for its activities in the Central African Republic.

Chollet also urged Serbia to introduce sanctions against its traditional Slavic ally Russia.

“We believe that countries should sign on to the sanctions, and the reason why we believe that is because Russia’s actions do not only have to be condemned, they have to be punished,” he said. “Russia every day is prosecuting a brutal, unjustified war against Ukraine. We need to stand together, to ensure that this behavior, it’s clear that this behavior is unacceptable.”

The U.S. envoy this week launched a tour of several Balkan nations in a visit focused on international efforts to help normalize relations between Kosovo and Serbia after weeks of heightened tension. The former Serbian province declared independence in 2008, something Serbia and Russia don’t recognize. Source: Voice of America