Mr Mwanawasa is expected to run for a second term in office

"I am very well, although I am not fully recovered, and my illness will not affect my work," he said.

He may be able to return home from the United Kingdom this Friday, he said.

Mr Mwanawasa, 57, has been in office since 2001, and has said he intends to contest elections later this year for a second and final term.

"I don't intend to break until I have broken the yoke of poverty that holds Zambians," he said.

There has been speculation in Zambia over the cause of Mr Mwanawasa's illness, prompting opposition groups to demand more information.

Mr Mwanawasa cancelled an election campaign trip and flew to London to see doctors after feeling ill on 1 April, officials said.

But a government spokesman said Mr Mwanawasa had gone to London for a routine check-up to ensure his fitness ahead of the election campaign.