aftar commands the Libyan National Army, which began an offensive to seize Tripoli from the United Nations-backed Government of National Accord in April.
On Wednesday, Amnesty International revealed new evidence of war crimes in Libya, including indiscriminate attacks on civilian residential areas.
Amnesty said satellite images and witness testimony indicated that "densely populated residential areas in the Abu Salim district of Tripoli were indiscriminately attacked with rockets during an episode of intense fighting between 15-17 April."
Haftar's forces and a local militia affiliated with the Government of National Accord blamed each other for the indiscriminate attacks in southern Tripoli. Residents interviewed by Amnesty told the nongovernmental organization that they believed Haftar's forces were responsible.
Libya has been plagued by violence since the ouster and killing of longtime strongman Moammar Gadhafi in 2011.
More than 400 people have been killed in the latest offensive and more than 2,000 wounded, according to the World Health Organization. The UN's humanitarian affairs office said more than 60,000 people have fled their homes.
Trump was strongly criticized for praising Haftar last month as his forces moved in on the capital. The White House's official readout of a phone call between Trump and Haftar made no mention of the offensive on Tripoli, which Secretary of State Mike Pompeo had criticized earlier in April.
Even after that call, Trump has not picked a side in the Libya conflict, a source familiar with internal White House discussions about the issue told CNN, adding that the President had agreed to speak with Haftar at the request of Egyptian leader Abdel Fattah el-Sisi.
Trump had met with Sisi at the White House in early April.
For now, Trump has decided to remain uninvolved in Libya until there is a winner -- and he will let the winner be established through a civil war or a political settlement, the source said, noting that Trump is aware of the Obama administration's failures when it comes to Libya
and does not want to repeat those mistakes.