Pope Francis on Saturday called on leaders to dispel the "dark clouds of war," speaking in a country sandwiched between two world powers - Russia and China - he has targeted in a Vatican diplomatic effort over Ukraine.
On his first working day in Mongolia, Francis attended an elaborate outdoor welcoming service that included a parade spanning the centuries, ranging from soldiers in modern dress uniforms to men on horseback dressed like ancient Mongol warriors.
He sat alongside President Ukhnaagiin Khurelsukh, who wore a traditional robe, wide-brimmed Mongol hat and boots. The two later met privately in a ger, a traditional round, nomadic tent-like home, set up inside the state palace.
Francis, 86 and in need of a wheelchair and cane, arrived in Mongolia on Friday and rested for the day to get used to the time difference. The primary purpose was to visit Mongolia's tiny Catholic community, which at 1,450 members in one of the smallest in the world.
In a speech to the president, government leaders and the diplomatic corps, Francis said he was a "pilgrim of friendship who comes to you quietly".
He spoke of Mongolian history, noting the vast country north of China is marking 860 years since the birth of Ghengis Khan, who united the Mongol tribes and instituted a period of peace known as the "Pax Mongolica". He gave the president a copy of a missive between Pope Innocent IV and the third Mongol emperor, Guyug, in 1246.
But then he took up modern-day issues.
"May Heaven grant that today, on this earth devastated by countless conflicts, there be a renewal, respectful of international laws," he said.
"May the dark clouds of war be dispelled, swept away by the firm desire for a universal fraternity wherein tensions are resolved through encounter and dialogue, and the fundamental rights of all people are guaranteed," he said.
Francis has sent an envoy, Italian Cardinal Matteo Zuppi, to Kyiv, Washington and Moscow to discuss ways of ending the conflict in Ukraine and aiding humanitarian efforts. Zuppi is due to go to Beijing soon.
Mongolia's proximity to China, of which it was part of until 1921, has brought attention to the Vatican's difficult relations with Beijing. The two sides signed an accord in 2018 on the appointment of Catholic bishops, but Beijing has violated it several times since then.
A few dozen Chinese nationals waving flags were in the crowd outside the palace during the welcoming ceremony on Saturday morning.
In his speech, Francis also spoke of threats to the environment, saying native Mongolian nomadic traditions respected nature's delicate balance but that today there was a need to "combat the effects of human devastation" of the environment.
Ulaanbaatar is one of the most polluted cities in the world, largely as a result of coal burning in winter.
Mongolia is one of the countries most affected by climate change, with average temperatures rising by more than 2 degrees Celsius since 1940.
With rainfall in long-term decline, around three-quarters of Mongolia's land is blighted by desertification and drought, and more than 200 small lakes have dried up since 1980.
Ecological problems have been aggravated by overgrazing, with around 80 million animals now trying to survive on land that can sustain only half that number, according to government figures.
The exploitation of mineral resources, seen as one of the only ways to grow the economy, has also put pressure on scarce water supplies.
Francis announced on Wednesday that he would release a new document on the protection of nature to update his landmark 2015 encyclical.