"It's the US position that Kadhafi has to leave and it is a challenge for anybody to put a timetable to that," the chairman of the US joint chiefs of staff told a news conference on a visit to Cairo.
"From a military perspective, everything I see indicates a continued drum beat to continue to raise the pressure, if you will, to force Kadhafi to depart.
Asked whether NATO would stop its air campaign without the Libyan strongman leaving office, Mullen said: "In that regard, certainly we'd like to see this end as soon as possible."
But he conceded that so far the campaign had made slow progress.
"What I have seen is what I would call very slow progress -- more and more individuals from his regime who are defecting, some of whom who are from the military."
Copyright AFP (Agence France-Presse), 2011