The statement from Jerusalem's Hadassah Hospital said Sharon's condition, unchanged overnight, is critical but stable. Doctors began removing anesthetics on Monday, and say the Israeli leader has responded to pain stimuli with slight movements of his right leg and arm.
Sharon remains hooked up to a respirator and unconscious, in a guarded room where classical music is being played.
Sharon, 77, has been in a medically-induced coma since his stroke, a state doctors felt would give him a better chance to heal. Doctors Monday began the process of bringing him out of the coma, by gradually reducing the amount of sedatives in his system, and Sharon responded by breathing on his own, and later, with the arm and leg movements.
Sharon's chief surgeon said the leader's response to pain stimulation is "very important" but it is too early to assess Sharon's ability to think and reason. It will take several days for all the sedatives to be withdrawn.
By Monday afternoon, Sharon had begun breathing on his own, though he is still on a respirator to assist him, said Dr. Shlomo Mor-Yosef, director of Hadassah Hospital, where Sharon is being treated.
Dr. Felix Umansky, the chief neurosurgeon treating Sharon, said doctors hoped that as the sedatives are further decreased that Sharon will have a greater response to pain stimulation, including opening his eyes.
"Once he talks to us ... and there are no other infections I will be willing to say that he is completely out of danger," Umansky said.
Israel's Ynet Web site quoted Sharon aides as saying. "The situation is much better than before. We're happy about the good signs."
Sharon suffered a severe stroke on Wednesday, two weeks after a first, mild stroke, and was rushed to Hadassah where he has undergone two surgeries to stop bleeding in his brain.
Although it is too early to know for sure, medical experts say it is likely that Sharon suffered some brain damage and paralysis.
Doctors will pass their assessment of Sharon's medical condition to Attorney General Meni Mazuz, who will decide whether to declare the prime minister permanently incapacitated.
"The minute we know what damage has occurred, we will talk," Justice Ministry spokesman Yaakov Galanti said.
Since an acting prime minister is in place, there is no urgency to such a declaration, Galanti added.
Ehud Olmert, Sharon's deputy, has been named acting prime minister and can serve in that role for 100 days.