TRIPOLI, Libya — The Libyan government has conceded that Foreign Minister Moussa Koussa has resigned but says the regime still enjoys the support of his people.

Koussa's defection to London has been hailed by the rebels as a sign that Moammar Gadhafi's regime is cracking at the highest levels. But government spokesman Moussa Ibrahim said Thursday that Koussa's decision was personal and "other people will step in and do the job."

Ibrahim says Koussa had been given permission to go to Tunisia because he was sick with diabetes and high blood pressure. He says the regime didn't know he would go to London.

Koussa arrived in Britain Wednesday on a flight from Tunisia.