General Salifou Mody, one of the officers behind the coup in Niger, visited Mali on Wednesday and met with officials from the country.
Mody and his delegation attended a meeting with Col. Assimi Goita, who seized control of the landlocked West African country nearly three years ago.
Western countries fear that Niger will fall under Russia's influence after the coup, especially as Mali has welcomed up to 1,000 fighters from the Wagner Group.
Burkina Faso and another military junta-led Mali, have taken the unusual step of declaring that foreign military intervention in neighboring Niger after last week's coup would be considered a declaration of war against them, too.
Part of the frustration in Niger and its neighbors over government weaknesses in addressing corruption and the threat from Islamic extremism has been aimed at France, the former colonizer of present-day Mali, Guinea, Niger, Burkina Faso and others in west and central Africa.
Russia has played into such sentiments by framing itself to African nations as a country that never colonized the continent, winning support in Mali and other vulnerable nations for Moscow and the Russian mercenary group Wagner.
In one of few addresses to the West African country since seizing power from Niger’s democratically elected president a week ago, Gen. Abdourahmane Tchiani warned against foreign meddling and military intervention against the coup.