The condition of Mr Yasser Arafat remains unclear tonight after Israeli television reported the Palestinian leader was "brain dead".
News agencies are reporting that the Palestinian leader is "brain dead" and breathing only thanks to artificial life support systems.
The AFP news agency is quoting a French medical source as saying Arafat was "not dead" in strictly medical terms.
However, on condition of confidentiality, the source said the 75-year-old leader had slipped into an irreversible coma and could only be maintained in his vegetative state through ventiliation machines.
A spokesman for the hospital in which Mr Arafat is being treated earlier denied he had died.
The Palestinian Authority president's condition was "complex," General Christian Estripeau, the spokesman for the French defence forces' medical service, told reporters outside the Paris military hospital which had been tending to Arafat.
"The patient's condition needs appropriate treatment which required his being transferred to a unit suited to his pathology on the afternoon of Wednesday November 3," he said. He refused to take questions, but said his statement had been prepared according to the wishes of Arafat's wife, Suha.
Earlier Israeli TV cited cited security officials as saying they had been told by a reliable French source that Mr Arafat had died.
Palestinian officials in Paris and the West Bank spent the day denying the reports of Arafat's demise, but said their leader was in a "critical condition" in the hospital's intensive care unit.
President George W. Bush, reacting to disputed reports this evening that Palestinian Prime Minister Yasser Arafat was dead, said "God bless his soul" and promised to work toward a free Palestinian state.
"My first reaction is God bless his soul," Mr Bush told a news conference when asked about reports that Arafat was declared clinically dead in a French hospital. "And my second reaction is we will continue to work for a free Palestinian state that's at peace with Israel."
Mr Arafat was rushed from his shell-battered compound in Ramallah to France on Friday with severe stomach pains and what doctors said could be leukaemia.
Doctors in Paris had earlier said that Arafat was in a coma while his top advisor had said that he was in a critical condition.
French President Jacques Chirac briefly visited Mr Yasser Arafat in the intensive care unit earlier today.
Mr Chirac "saw president Arafat and his wife (Suha) and expressed his wishes," his spokesman told journalists. "He spoke with doctors who are doing everything possible for the Palestinian Authority president's health," the spokesman said.
Mr Arafat was rushed to France from the West Bank last Friday with severe stomach pains, diarrhoea and vomiting. His illness has raised fears of chaos among Palestinians locked in a four-year-old uprising, and could change the political environment in the Middle East.
Mr Arafat has named no successor since emerging from exile under interim peace accords with Israel in the early 1990s.
Until he was airlifted to France, Mr Arafat had been effectively confined to his shell-shattered Ramallah headquarters by Israeli forces for two-and-a-half years.