Pope South North Korea
Pope Francis and South Korea's President Park Geun-hye inspect the guard of honour on his arrival at Seoul Air Base in Seongnam Reuters

North Korea fired three rockets into the Sea of Japan just an hour before Pope Francis arrived in Seoul for his first visit to Asia.

The alleged 'test-firings' came in two stages; three earlier short-range projectiles were launched before the Pontiff arrived on the Korean Peninsula, followed by two additional projectiles.

Speaking on condition of anonymity, a Defence Ministry official confirmed that the rockets were launched from Wonsan on the east coast of North Korea.

"North Korea fired three short-range projectiles into the East Sea (Sea of Japan)," a Defence Ministry spokesman added.

The Pope is to spend five days in South Korea, meeting a number of the country's Catholic population, which is estimated at five million. The papal visit is the first to the country in 25 years.

As he set off for the Asian country, he tweeted in Korean: "Starting my journey to South Korea and thank you for joining me in prayer for global love in Korea and Asia."

He is to hold a "reconciliation" mass in Seoul on the final day of his trip where it is anticipated that he will direct a message of peace towards Pyongyang.

Church officials in South Korea said that they had requested North Korea's attendance in the form of a group of Catholics but Pyongyang declined over its anger at forthcoming US-South Korea military drills.

Upon arrival at an airbase, he was greeted by South Korea president Park Geun-hye, a delegation of South Korea Catholics and relatives of the victims of the Sewol ferry disaster.

In a briefing with reporters on his plane, Pope Francis noted the importance of the media in promoting peace in a divided 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.