(Updates with arrival, details)
By Philip Pullella
SEOUL, Aug 14 (Reuters) - Pope Francis arrived in the South Korean capital Seoul on Thursday after sending an unprecedented message of good will to China as he flew over the country that does not allow its Catholics to recognise his authority.
Francis will spend five days in South Korea, meeting some of the country's five million Catholics on the first trip by a pontiff to Asia since 1999.
"Upon entering Chinese air space, I extend best wishes to your Excellency and your fellow citizens and I invoke the divine blessing of peace and well-being upon the nation," he said in a radio message to President Xi Jinping.
It was the first time a pope had been allowed to fly over China on Asian tours. His predecessor John Paul II had to avoid Chinese airspace because of the fraught relations between Beijing and the Vatican.
The Vatican has had no formal relations with China since shortly after the Communist Party took power in 1949. The Catholic Church in China is divided into two communities: an "official" Church known as the "Patriotic Association" answerable to the Party, and an underground Church that swears allegiance only to the pope in Rome.
Francis did not mention China or the divided Korean peninsula in his brief chat with reporters on the plane but instead insisted on the media's role in promoting peace in a divided and violent world.
"May your words help unite ... I ask you to always give a message of peace, always seek a message of peace because what is happening (in the world) now is ugly," he said.
After being told about the death of a television cameraman in Gaza, Francis led journalists aboard the plane in a minute of silent prayer in his memory.
The pope was greeted at an air base in southern Seoul by South Korean President Park Geun-hye with a delegation of South Korean Catholics including two North Korean defectors, as well as relatives of victims of the Sewol ferry that capsized in April, killing about 300 passengers, most of them school children.
"The disaster is heart-breaking, I have not forgotten the victims," South Korea's Yonhap news reported Pope Francis as saying to members of the welcome delegation.
"Peace on the Korean peninsula has always had place in my heart," he said.
The pope was scheduled to attend a formal welcoming ceremony later in the day, in order to allow the 77-year-old pontiff several hours for rest after the long flight.
Pope Francis has on previous foreign visits opted to ditch his bulletproof 'Popemobile' car in favour of more modest modes of transportation. In Seoul, he was picked up at the end of the red carpet in a dark grey Kia Soul hatchback.
The visit, the main purpose of which is for the pope to preside at a gathering of Asian Catholic youth, is the third international trip by Francis since his election in March 2013. (Additional reporting by James Pearson and Ju-min Park; Editing by Tony Munroe and Jeremy Laurence)