President Jalal Talabani, a Kurd who has been a pivotal mediator among Iraq's fractious Shi'ite, Sunni and Kurdish parties, was hospitalized in Baghdad because of a "health emergency", his office said on Tuesday, Reuters reported.
Talabani's office gave no further details of his medical condition, but a senior source in his Patriotic Union of Kurdistan or PUK party said the president, who is 79, was admitted to hospital for exhaustion.
"A specialized medical team is taking care of him and a report will be issued later," the statement from the presidential office said.
Prime Minister Nuri al-Maliki visited Talabani at the Baghdad hospital on Tuesday.
Should Talabani be incapacitated, Iraq would lose an influential negotiator who often stepped in to ease tensions in the fragile power-sharing government, including during a recent attempt to push a vote of no confidence against Maliki.
He has been suffering from ill health this year and received medical treatment overseas several times in the last two years.
According to Iraq's constitution, the parliament should elect a new president if the post becomes vacant. Under Iraq's power-sharing deal the presidency should go to a Kurd while two deputy president positions are shared by a Sunni Muslim and a Shi'ite Muslim.
Mediation by Talabani recently helped reduce friction between Maliki's central government and the autonomous Kurdistan president, Masoud Barzani, in a dispute over oilfield rights and internal boundaries.
A veteran of the Kurdish guerrilla movement, Talabani survived wars, exile and infighting in northern Iraq to become the country's first Kurdish president a few years after the 2003 invasion that toppled Saddam Hussein.