Russian military officials including Moscow's deputy defence minister arrived in Libya on Tuesday after receiving an invitation from pro-Moscow warlord Khalifa Haftar.
Haftar, who backs the country's eastern administration, is close to Russia's private Wagner mercenary group, whose troops guard military and oil infrastructure in the divided country.
Libya is split between the United Nations-supported government of Prime Minister Abdelhamid Dbeibah in Tripoli, and a Haftar-backed administration in the east.
A UN report in 2020 said up to 1,200 Wagner fighters were backing Haftar, who at the time was trying to seize Tripoli. His offensive lasted more than a year but was unsuccessful.
Experts say hundreds of Wagner fighters remain in the north African country.
Tuesday's visit came alongside a renewed focus on Russian activities in Africa, after Wagner chief Yevgeny Prigozhin announced in a video published Monday that his group was making Africa "freer" and suggested he was on the continent.
"This is the first official visit of a Russian military delegation to Libya," Moscow's defence ministry said.
It said the visit, led by Deputy Defence Minister Yunus-bek Yevkurov, was organised after talks with Libya at the Army-2023 expo and Moscow Conference on International Security earlier this month.
"During the visit, it is planned to discuss prospects for cooperation in combating international terrorism and other issues of joint action," Moscow's defence ministry added.
According to a statement from Haftar's spokesman, Ahmad al-Mesmari, the Russian delegation met senior officers in Haftar's forces.
The two sides examined their "cooperation and coordination" regarding "training... and the maintenance of Russian weapons and equipment" which is the "vertebral column" of Haftar's forces, the statement said.
Wagner maintains a strong military presence in Africa, where it has partnered with several nations, including Mali and the Central African Republic.
Prigozhin, a former Kremlin ally whose group rebelled against Russia's military leadership in June, has made few public appearances since the mutiny.