The Zambian government says President Levy Mwanawasa has suffered a stroke.
The president was hospitalized Sunday in the Egyptian resort of Sharm El Sheikh, where he was preparing to attend Monday's summit of African Union leaders.
Zambian Vice President Rupiah Banda says in a statement Monday that Mr. Mwanawasa is being attended to by doctors and his condition is stable.
The Zambian president fell ill on Sunday after attending an AU committee meeting on United Nations reform. An initial statement from Zambia's foreign minister had described his ailment as a consequence of high blood pressure.
The AU summit has so far focused largely on the political crisis in Zimbabwe. Mr. Mwanawasa is known as a critic of Zimbabwean President Robert Mugabe, but has said he will not comment on the current situation before AU leaders discuss the matter.
Some information for this report was provided by Reuters.