Experts say Moscow is looking to gain a foothold in the North African nation with its backing for Marshal Khalifa Haftar, based in Libya's east and one of the country's most powerful figures since the ouster and killing of Moamer Kadhafi.
Russia has been cultivating Haftar as an ally, with the military chief making several visits to Moscow last year.
The emerging alliance could not have been more clear than when a Russian aircraft carrier -- fresh from completing a two-month mission off Syria in support of President Bashar al-Assad's forces -- welcomed Haftar earlier this month.
The Admiral Kuznetsov parked off the coast of the eastern Libyan town of Tobruk to take Haftar on board, where he met with Russian officers and spoke via video link to Russian Defence Minister Sergei Shoigu.
"Moscow is clearly testing the waters with respect to tipping the political and military balance towards Libya's east," said Ethan Chorin, a former US diplomat posted in Tripoli and now CEO of consulting firm Perim Associates.
Moscow is looking, he said, "to project influence in the southern and eastern Mediterranean and (for) increased influence over Libya's oil and gas resources."
Haftar served in the army under Kadhafi but later turned against the longtime Libyan leader and spent years in exile in the United States.
Push to lift arms embargo
He returned to Libya and played a senior role in the forces that overthrew Kadhafi in the 2011 NATO-backed uprising.
The years since have seen Libya thrown into turmoil, with rival factions and militias vying for power.
Last year after months of UN-backed talks, a Government of National Accord (GNA) emerged as the centrepiece of Western hopes for a proper administration, but it has failed to assert its authority over the whole of Libya.
Haftar has instead thrown his support behind a rival administration backed by a parliament based in Tobruk which has recognised him as the head of Libya's national army.
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Clashes have broken out several times between Haftar's troops and pro-GNA forces -- who include powerful militias from the western city of Misrata and who won a major victory last year by driving Islamic State group jihadists from the coastal city of Sirte.
In a key turning point, Haftar's forces in September seized four oil export terminals from pro-GNA fighters in eastern Libya.
Haftar has been pushing for the United Nations to lift an arms embargo imposed on Libya and sought Russian support for the move during a visit to Moscow in November.
He told Italy's Corriere della Sera earlier this month that he was assured during the visit that "Putin will undertake to revoke it".
"Haftar's expectation is that Moscow will push for lifting the arms embargo altogether or at least get an exemption" for his forces, said Mattia Toaldo, senior policy fellow at the European Council on Foreign Relations.
Looking to Trump
That would cement Russian support for Haftar, who is already backed by Arab nations including Egypt and the United Arab Emirates.
Europe and the United States have so far supported the GNA -- with US forces carrying out dozens of air strikes in support of its forces in Sirte -- but Toaldo said that could change.
US President-elect Donald Trump's incoming administration is expected to seek better ties with Russia and President Abdel Fattah al-Sisi in Egypt.
"A convergence of Russia, Egypt and the Trump administration on Haftar should not be excluded especially in light of the position expressed by members of Trump's team that the Muslim Brotherhood is equivalent to Al-Qaeda or IS," Toaldo said.
Analysts say the Libyan branch of the Brotherhood -- a longstanding pan-Arab Islamist movement that Sisi forced out of power in Egypt -- is among the key factions backing the GNA.
During his confirmation hearings earlier this month, Trump's secretary of state nominee Rex Tillerson lumped the Brotherhood in with IS and "other agents of radical Islam" like Al-Qaeda.
Analysts worry that Russian support will encourage Haftar to seek further confrontation with pro-GNA forces in the west, potentially returning Libya to a full-blown civil war.
"Haftar's international backers appear to believe that the Trump administration could be convinced to... turn a blind eye as Haftar engages in a re-invigorated military confrontation with militias in western Libya," said Jason Pack, a Britain-based Libya analyst, researcher and monitor.
"The practical outcome would be to hand Russia the leading role in Libya's future as well as a further outpost on the Mediterranean."