The Vatican on Friday said the leader of one billion Roman Catholics had spent a peaceful night in hospital after surgery to pass a tube through his throat down into his lungs to help him breathe.
His tracheotomy means he will not be able to speak "for some days", Vatican spokesman Joaquin Navarro-Valls said. But the Pope managed to have breakfast consisting of a cafe latte, yoghurt and small Italian 'biscotti', consuming it "with a good appetite".
The 84-year-old Pope, who was hospitalised on Thursday for the second time in less than a month after a relapse of flu, has reigned for 26 years and is for many younger Catholics the only pontiff they have ever known.
His very public battles against Parkinson's disease and his failing health have won him a special place in the hearts of many of the world's Catholics as well as many non-Catholic leaders.
US President George Bush took the time while flying home from a whirlwind reconciliation tour with European leaders to send his best wishes to John Paul, who became the first non-Italian pope in four-and-a-half centuries.
"The holy father is in our thoughts and prayers and we wish him a speedy recovery and return to the service of his church and of all humanity"
"The holy father is in our thoughts and prayers and we wish him a speedy recovery and return to the service of his church and of all humanity," Bush said in a statement.
During the build-up to the war in Iraq, the Vatican became an obligatory stopover for world leaders seeking to overturn the pope's fierce opposition to any invasion of the country - a stance in which he never wavered.
The first Pope from eastern Europe, Karol Wojtyla is seen as the 263rd direct successor to Saint Peter as Bishop of Rome.
There are four possible candidates from Latin America who could be named to succeed John Paul should he finally succumb to his years of ill health.