Libyan and U.S. officials say representatives from the two governments held direct talks recently, but Washington stressed that the sole objective was to deliver a "clear and firm" message that Libyan leader Moammar Gadhafi must leave power.
A U.S. State Department official Monday said the one-time meeting "was not a negotiation," and that the only way forward is for Mr. Gadhafi to "step down."
He said the discussion took place Saturday and involved Assistant Secretary of State Jeffrey Feltman, the top State Department official in charge of Middle East policy. Four members of Mr. Gadhafi's inner circle also participated.
The U.S. official said the meeting was initiated after repeated contacts from Mr. Gadhafi's emissaries that Washington interpreted as a misguided attempt to repair relations.
Earlier, Libyan government spokesman Moussa Ibrahim described the talks, which were held in Tunisia, as "a first step dialogue." He said the Libyan government does "not want to be stuck in the past" and would welcome further negotiations.
Ibrahim said in June that Mr. Gadhafi would not consider any peace initiative that would require him to step down.
The meeting followed a decision Friday by the U.S. and more than 30 other nations to formally recognize the Benghazi-based rebel Transitional National Council as Libya's legitimate interim government.
Libyan officials have said previously that envoys of Mr. Gadhafi have conducted talks with anti-government rebels. But officials with the opposition council have denied that.