The eastern commander General Haftar, whose troops are currently attacking Tripoli, has spoken to President Trump, according to the White House.
On Monday, a call was made by Mr Trump who discussed Libya’s future with Gen Haftar. President Trump also didn’t hold back his recognition for Gen Haftar’s efforts in combatting terrorism and securing Libya’s oil.
Tripoli, the capital, is the seat of Libya’s United Nations-backed and internationally recognised government.
And unlike some of his allies, President Trump’s call has suggested he fully endorses Gen Haftar.
Since fighting began close to a month ago, close to 300 people have been killed so far.
The UN-backed PM Fayez al-Serraj has condemned the assault by General Haftar’s troops on his international allies.
Since Muammar Gaddafi was killed in 2011, Libya has been severely wrecked by violence and political instability.
In what Mr Serraj described as an attempted coup, Gen Haftar’s eastern forces descended on the capital city – Tripoli – as that started the latest crisis.
Receiving word that Gen Haftar has seized Tripoli’s international airport, his troops are advancing from various directions on the outskirts of the city.
The White House said during President Trump’s conversation with Gen Haftar, they “discussed a shared vision for Libya’s transition to a stable, democratic political system”.
Alan Johnston, BBC’s Middle East Regional Editor says that the call to Gen Haftar seems to signify that Washington is putting its weight behind Gen Haftar and sees him as Libya’s surest bet to restoring order to the country.