Pope Francis on Sunday sent greetings to China, calling the nation's citizens a "noble" people and asking Catholics in China to be "good Christians and good citizens".

Francis made the unscripted comments at the end of Mass on his visit to Mongolia, calling up the former and current bishops of Hong Kong, Cardinal John Tong and Bishop Stephen Chow, to flank him as he spoke.

"These two brother bishops – the emeritus of Hong Kong and the current bishop of Hong Kong. I would like to take advantage of their presence to send a warm greeting to the noble Chinese people," he said in Italian.

"I wish the best for all the (Chinese) people, to go forward, to always progress. And to Chinese Catholics I ask to be good Christians and good citizens," he said.

On Saturday, Francis said governments have nothing to fear from the Catholic Church because it has no political agenda.

The Mass in Ulaanbaatar's Steppe Arena was the religious highlight of the pope's trip to visit the Catholic community of just 1,450 – believed to be the world's smallest per capita in a Mongolian population of about 3.3 million, most of them Buddhists.

Most of Mongolia's nine parishes are in the capital, but one in a remote area has only about 30 members and Church officials said they expected everyone who could make it to attend.

Many Mongolians still live a nomadic tradition to graze their animals and in his homily, the pope used the image to get his point across.

"All of us are God's nomads, pilgrims in search of happiness, wayfarers thirsting for love," he said, adding that the Christian faith quenched that thirst. (Reuters)