Burkina Faso summoned the Ghanaian ambassador on Friday morning for “explanations” after Ghana’s president alleged that Burkina Faso had hired the Russian mercenary group Wagner, Burkina Faso’s foreign ministry said.

Speaking to reporters alongside U.S. Secretary of State Antony Blinken on Wednesday, Ghana’s President Nana Akufo-Addo alleged that Burkina Faso had hired the mercenaries.

“Today, Russian mercenaries are on our northern border. Burkina Faso has now entered into an arrangement to go along with Mali in employing the Wagner forces there,” Akufo-Addo said, adding that it was a distressing development for Ghana.

Akufo-Addo also alleged that Burkina Faso had offered Wagner a mine as payment.

In a statement issued after the meeting with the ambassador, Burkina Faso’s foreign ministry said it had “expressed disapproval” about the statements made by the Ghanaian president.

“Ghana could have undertaken exchanges with the Burkinabe authorities on the security issue in order to have the right information,” it said.