The representative of the Libyan opposition government left the White House late Friday after receiving warm words of encouragement but not the hoped-for official recognition, officials said, DPA reported.
Tom Donilon, US national security advisor, told Mahmoud Jibril that the US considered his rebel Interim Transitional National Council to be the "legitimate and credible interlocutor of the Libyan people," a White House statement said.
Regime leader Colonel Moamer Gaddafi had "lost his legitimacy to rule" Libya, the statement said, reiterating President Barack Obama's call for him to "leave immediately."
But no mention was made of any official recognition by the US of Libya's self-appointed interim government, which is currently only recognized by France, Qatar, Maldives, Italy, Kuwait, and Gambia.
On Thursday, US Defence Secretary Robert Gates said Washington's hesitation to throw its weight behind the rebels was in part because "we don't know who they are."
The US president did not attend Friday's meeting with the Libyan leader. But he did speak with NATO Secretary General Anders Fogh Rasmussen at a meeting in Washington, where the two agreed to continue the alliance's air campaign to protect Libyan civilians against government troops.
On Friday, a recorded audio message from Gaddafi was broadcast, denying he had been injured in recent NATO bombings of his residential compound, which have killed one of his sons and three of his grandchildren.
Observers have speculated he might be wounded or have fled the country.
NATO has conducted 2,512 strike sorties on Libya since it assumed control of operations late March. The opposition estimates that over 12,000 people have been killed since mid-February, when the uprising to oust Gaddafi from power began.
Russia has criticized NATO's intervention, saying the operation violates United Nations' rules of sovereignty.