President Donald Trump spoke this week with Khalifa Haftar, the Libyan warlord fighting to capture the capital Tripoli, the White House said Friday.
President Trump and Mr Haftar spoke on Monday "to discuss ongoing counterterrorism efforts and the need to achieve peace and stability in Libya," according to the White House press office.
The statement said that Mr Trump "recognised Field Marshal Haftar's significant role in fighting terrorism and securing Libya's oil resources".
In their phone call, "the two discussed a shared vision for Libya's transition to a stable, democratic political system."
The White House did not say why it delayed giving news of the phone call.
Mr Haftar launched an offensive on April 4 to seize Tripoli, a move that threatened to plunge the north African country into even deeper turmoil.
Mr Haftar, seen by his allies Egypt and the United Arab Emirates as a bulwark against Islamists, has declared he wants to seize the capital, now controlled by a UN-recognised government and an array of militias.
The military commander backs a rival administration based in eastern Libya that is refusing to recognise the authority of the Tripoli government.
A British bid at the UN Security Council to demand a ceasefire in Libya was opposed Thursday by Russia and the United States.
Russia insisted on having no criticism of Mr Haftar in the proposed resolution while the United States said it wanted more time to consider the situation, diplomats said.