Details added (the first version was posted at 16:40)
Iraq's Foreign Minister Hoshyar Zebari told Al Arabiya on Tuesday that President Jalal Talabani was not dead.
President Talabani a Kurd who has mediated among the country's Shiite, Sunni and Kurdish parties, was in hospital on Tuesday after suffering a stroke that left him in "critical but stable condition," government sources said.
Should Talabani be incapacitated, Iraq would lose an influential negotiator who often stepped in to ease tensions in the fragile power-sharing government and between the central government and the country's autonomous Kurdistan region.
Talabani's office said he was admitted to a Baghdad hospital on Monday night and the 79-year-old president was in stable condition under intensive medical supervision after receiving treatment for blocked arteries.
"He was transferred to hospital late last night after suffering a stroke," a senior Kurdish official said.
Talabani had been suffering from ill health this year and received medical treatment overseas several times in the last two years.
Prime Minister Nuri al-Maliki visited the president at the Baghdad hospital on Tuesday.