Francis took the decision after recognizing that John Paul II had performed a second miracle after his death, while he decided to waive the second-miracle requirement -- usual in sainthood causes -- for John XXIII.
The canonization of the two late pontiffs will "presumably" take place "before the end of the year," Vatican spokesman Father Federico Lombardi said.
The Italy-born Angelo Roncalli served from 1958 to 1963 and led the Catholic Church toward major reforms by opening the Second Vatican Council in 1962, which concluded three years later under his successor Paul VI.
"We all know the virtues and the personality of pope Roncalli, there is no need to explain the motives of his sainthood," Lombardi told reporters.
The Polish-born Karol Wojtyla, whose papacy under the name of John Paul II lasted from 1978 to 2005, is remembered for his charisma and his role in bringing down communist rule in Eastern Europe, starting from his home country.
The Vatican certified that a Costa Rican woman recovered from brain damage through his intercession on May 1, 2011 -- the day he was beatified, the ANSA news agency said. That miracle added to the curing of a nun from Parkinson's disease two months after his death.
John Paul II's rise to sainthood has been one of the fastest in modern times. Crowds chanted "santo subito" (saint now) at his funeral, and his successor Benedict XVI immediately started the process, waiving the normal five-year wait after a candidate's death.
John XXIII -- who is known in Italy as the "papa buono" (the good pope) -- was beatified by the then-ruling John Paul II in 2000, after he was credited with the 1966 curing of an Italian nun from serious stomach bleeding and infection.
Francis recognized several other miracles and martyrdoms on Friday, allowing for the beatification of Spanish bishop Alvaro Del Portillo, former head of Catholic conservative group Opus Dei, and of several priests killed during the Spanish cvil war.
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