Pope Francis arrived in Mongolia on Friday to begin the first papal visit to the vast Buddhist-majority nation, which is landlocked between China and Russia.
The pontiff, 86, who has had health concerns in recent years, arrived at Ulaanbaatar airport on a chartered ITA Airways plane.
He travelled with a large entourage and journalists.
The Pope was greeted by Mongolian honour guards wearing traditional blue, red and yellow attire and the country's Foreign Minister Batmunkh Battsetseg.
The pontiff's trip has been viewed as a gesture of support for Mongolia's community of about 1,400 Catholics.
His first official event in Mongolia is on Saturday, when he is to address government leaders and the diplomatic corps.
The pontiff will later meet members of the Catholic community, which includes 25 priests and 33 nuns, only two of them Mongolian, in Saints Peter and Paul Cathedral.
Its circular nave resembles a ger, the traditional tent dwelling of Mongolian nomads.
The visit, the Pope's second to the region in a year after a trip to Kazakhstan last September, is also geopolitically significant.
His arrival has been described as an effort to encourage Mongolia's fragile democracy and potentially help the Catholic Church build ties with Mongolia's more powerful neighbours.
"This is a clear effort of the Holy See to take care of Central Asia and not abandon it to Russia or China," Michel Chambon, a scholar of Catholicism in Asia, told AFP.
It is also crucial in keeping the door open for improved ties between the Vatican and Beijing and Moscow, which have not yet invited the Pope to visit.
"It's a way to not give up, to remind them 'I'm here'," Mr Chambon said.
"It's a way not to just stay in Rome and wait for things to happen, but to jump in."
As his nine-hour flight crossed Chinese airspace, the Pope, following custom, sent a telegram to President Xi Jinping, bearing "greetings of good wishes" to him and the country's people.
The visit – the pontiff's 43rd in his decade as head of the Catholic Church – will be a test of stamina. The Pope continues to travel widely despite undergoing a hernia operation in June and experiencing pain in his knee that has forced him to use a wheelchair.
On Sunday, he is to address an interreligious meeting that the rector of Ulaanbaatar's Russian Orthodox Church is expected to attend, before presiding over a Mass inside a new ice hockey arena.
Pilgrims from nearby countries including Russia, China, South Korea, Thailand, Vietnam, Kazakhstan, Kyrgyzstan and Azerbaijan are expected at the event, the Vatican said.