The illness of Unification Church founder Sun Myung Moon is "irreversible", the church said Friday, after he was hospitalised with complications from pneumonia more than two weeks ago.
Moon, 92, has critical organ failure and is on life support, it said in a statement.
Spokesman Ahn Ho-Yeol told AFP that Moon would be transferred from Seoul's St Mary's Hospital later Friday to a medical centre at the church's estate east of the capital.
Treating him on "holy ground" would have "greater providential significance", the church's International Vice-President Joon Ho Seuk said in a statement.
Seuk said that Moon's condition had appeared to be improving for a while, but in the past few days his doctors reported he had entered "an irreversible stage of his condition".
Moon's "kidneys have ceased to function, and the function of his liver is deteriorating rapidly", he said. "He can no longer sustain his life without the supply of oxygen artificially produced by a machine.
"In these circumstances, the officials at Seoul St. Mary's Hospital informed us that 'there is no longer any way to improve True Father's condition through modern medical technology'," said Seuk.
The phrase "True Father" refers to Moon, who the church says is "the one and only messiah in human history".
"The seven billion people of this world should stay up all night in prayer wishing for the recovery of True Father, who is so precious and dear to all of us, as he fights against his illness," Seuk said.
The Unification Church, set up by Moon in Seoul in 1954, is one of the world's most controversial religious organisations, and its devotees are often dubbed "Moonies" after the founder.
It is widely known for conducting mass weddings among followers involving thousands of couples. It says it evangelises in some 200 countries and according to another spokesman has some three million followers worldwide.
The church has a vast business empire, including The Washington Times newspaper, Manhattan's New Yorker Hotel and interests in North Korea, where Moon was born. He visited the country in 1991 to meet then-president Kim Il-Sung.