The most senior American diplomat yet to visit the rebels in Libya is holding talks in their strongold, Benghazi, the BBC reports Monday.
US Assistant Secretary of State Jeffrey Feltman has met the Transitional National Council, which rules the east of the country.
His visit comes after the EU foreign affairs chief, Catherine Ashton, also visited the city to open an EU office on Sunday.
Some countries - including France, Italy and Qatar - have already given diplomatic recognition to the TNC rebel leadership.
The Libyan rebels failed to gain full recognition when they travelled to Washington a week ago.
But after those talks the US President Barack Obama went as far as to say the Transitional National Council (TNC) was a "legitimate and credible" interlocutor for the Libyan people.
He added that it was inevitable that Colonel Muammar Gaddafi would leave power.
The Council of the European Union reiterated its call Monday for the protection of civilians and for a ceasefire and identifying Gaddafi as "a threat to the Libyan people."