National Zoo pandas set to make early return to China

It's panda-monium at the National Zoo for panda lovers who will have to say goodbye to the trio of bears earlier than expected.

Zoo officials told ABC News Wednesday morning that the date for the three giant pandas, Mei Xiang, Tian Tian and their cub Xiao Qi Ji to leave Washington, D.C., had been moved forward to mid-November, a few weeks prior to their originally scheduled return on Dec. 7. After they leave, the only remaining giant pandas in the United States will be in Atlanta.

The zoo is not releasing an exact departure date due to security concerns. It's not clear why the timing of the pandas' departure changed.

The three bears will make the 19-hour journey to China aboard a specialized FedEx "Giant Panda Express" plane.

The pandas will return to China as part of the agreement with the Chinese government first struck in December 2000, when Mei Xiang and Tian Tian arrived at the zoo.

The bears' departure will be bittersweet for their keepers.

"After working with the pandas for so many years, now, I'm very connected to them, and I have a lot of memories with them," keeper Mariel Lally said in September following the announcement that the bears would return to China. "So, them leaving is going to be really sad for me as it will be for all of the other giant panda keepers. But it's also something that we're really proud of. So, it's a bittersweet moment to say goodbye, because they have done so much for giant panda conservation."

"I am sad, you know, we've been able to work with these individuals, some of them 23 years. But it also means that we've been successful, and we've had a lot of wins to help save giant pandas both under human care and in the wild," Michael Brown-Palsgrove, the National Zoo's Curator of Asia Trail and Giant Pandas, told ABC News.

At the end of September, the National Zoo put on a week-long event called "Panda Palooza" to allow zoo goers to say goodbye to the pandas. The zoo encourages everyone to come see the pandas in the couple of weeks before their departure or to say goodbye via the Zoo's 24/7 panda cam.

Pandas have been at U.S. Zoos for some 50-years -- since President Richard Nixon first struck the agreement.

National Zoo officials remain tight-lipped about any prospects to renew or extend the agreement or any plans to bring other pandas to the zoo in the near future.