The US-born giant panda Bei Bei has left his home at Washington's National Zoo for China.
Bei Bei will travel on a specially equipped flight from Washington to Chengdu, accompanied by his keeper and a veterinarian.
The giant panda turned four years - the age when all pandas born outside return to China under their breeding agreements.
"Today is bittersweet. We've cared for Bei Bei, and along with millions, watched him grow into a true ambassador for his species," said zoo director Steve Monfort.
"We look forward to continuing our 47-year giant panda conservation program and collaboration with Chinese colleagues to study, care for and help save the giant panda and its native habitat."
Zoo officials said they had prepared a special stash of treats for him: 30 kilos of bamboo, two pounds of apples and pears, two pounds of cooked sweet potatoes, two bags of biscuits and water.
Presidents, royalty and simple mourners bade farewell to Pope Francis on Saturday at a solemn funeral ceremony, where a cardinal appealed for the pontiff's legacy of caring for migrants, the downtrodden and the environment to be kept alive.
US President Donald Trump and Ukrainian leader Volodymyr Zelenskyy, in Rome for the funeral of Pope Francis, met one-on-one in a marble-lined Vatican basilica on Saturday to try to revive faltering efforts to end Russia's war with Ukraine.
A large explosion rocked Shahid Rajaee port in the southern Iranian city of Bandar Abbas on Saturday, killing at least four people and injuring more than 500.
Pope Francis' wooden coffin was carried into St. Peter's Square on Saturday at the start of a funeral Mass attended by a multitude of mourners, including world leaders, pilgrims and prelates.