Sept. 17, 2012— -- Mei Xiang, the giant female panda at the Smithsonian's National Zoo in Washington, D.C., has given birth to a panda cub, according to the zoo.
Chief veterinarian Suzan Murray said the unnamed cub was born at about 10:46 p.m. Sunday night.
"Mother and cub are doing great," Murray said today on "Good Morning America" from the zoo. "We are so excited here at the Smithsonian National Zoo to have this cub."
This is Mei Xiang's second birth as the result of artificial insemination. She gave birth to her first cub, Tai Shan, in 2005. Tian Tian, 15, is the father of both of Mei Xiang's cubs.
Mei Xiang, 14, has had five consecutive pseudopregnancies since 2007 and had a less than a 10 percent chance of being pregnant after so many failed attempts.
"Mom is doing so great," Murray said. "She is definitely the poster child for the perfect "panda mom."
She keeps trying to doze because she is tired and the minute the cub squawks her head perks right on up and she cradles it and cuddles it. She is just perfect."
Veterinarians will perform the first physical exam after Mei Xiang and the cub have had time to bond, the zoo said. The new mother will most likely not come out of her den, or eat or drink, for at least a week.
"She [Mei Xiang] has a huge nest of bamboo, so it's normal not to see the cub," Murray said. "We rely a lot on the sound. We like to hear a little squawking and we're hearing a lot of squawking."
With only 300 pandas left in breeding zones and zoos around the world, Mei Xiang and the father of the new cub have become public symbols for endangered species and conservation efforts.
As part of President Hu Jintao's official state dinner welcome in January of 2011, the announcement was made of a new five-year, $2.5 million deal between the Smithsonian Institution and the China Wildlife Conservation Association. The Panda Cooperative Research and Breeding Agreement allowed Washington's furriest duo to stay in the nation's capital.
"Pandas are such a good ambassador for conservation and they highlight all that we do here at the zoo," Murray told "GMA." "Everybody is thrilled. We're thrilled nationally, globally. It's a nice image of the partnership we have with our Chinese colleagues."
U.S.-China relations have been never been simple. But panda diplomacy is not a new tactic in strengthening international ties. Since the Tang Dynasty from A.D. 618 to 907, China has been sending its national treasure to other countries as a symbol of gratitude.
The first panda couple to be donated to the American people followed President Richard Nixon's historic 1972 trip to China, one that marked a new beginning for the longtime foes. Greeted with an official ceremony hosted by the first lady, Ling-Ling and Hsing-Hsing lived at the National Zoo for more than 20 years.
ABC News' Reilly Dowd and The Associated Press contributed to this report.