Zoo Atlanta is one of just four zoos in the United States that has a panda exchange program with China. This so-called “panda diplomacy” has been a huge boon to the zoo.

Thursday marks an important day — two pandas who have entertained crowds for years are making a long journey to a homeland they’ve never seen.

CCTV America’s Sean Callebs reports.

For the past three years, the first surviving panda twins born in captivity in the U.S., Mei Lun and Mei Huan, have been the star attraction at Zoo Atlanta.

Now, as part of an exchange agreement with China, these two are making a long journey to Chengdu and the Giant Panda Research Base.

“I am a little emotional just thinking about It,” Stephanie Braccini, the Zoo Atlanta mammal curator, said.

Zoo Atlanta’s mammal curator Stephanie Braccini has watched the twins -blossom into fun-loving, entertaining sisters, and it’s only natural to have mixed feelings saying good-bye.

“We are happy knowing they are going – they will add to the diversity of the population. Their offspring –their offspring’s-offspring could be released into the wild,” Braccini said.

Mei Lun and Mei Huan have been so close ever since they were born. But pandas are solitary bears-and soon heading back to China. Within a year or two this is all going to change, they will actually become quite separate.

Three-year-old giant panda twins Mei Lun and Mei Huan will leave Zoo Atlanta today and return to China as part of a loan agreement with the Chengdu Research Base of Giant Panda Breeding. Here’s a look back when the pandas were just a few months old