"And from my perspective, it has been as good as it always is. Because we've had such a good relationship over so many years, we respond to each other so well."

She said she hoped the program "could last for at least another 50 years".

During the interview with Smith, Mei Xiang and Xiao Qi Ji frolicked in an outdoor field of the panda house, while Tian Tian leisurely chewed on bamboo in another field as visitors streamed in to observe the pandas.

Brooklyn, a 3-year-old girl, told China Daily that she wanted "more panda mommies and panda babies" to come to the zoo.

Sue, 62, who was on her annual family vacation, had just visited the pandas at Zoo Atlanta and was now seeing the pandas in Washington.

"I have been to Chengdu (home of the Panda Reserve in Sichuan province) for a vacation," she said, adding that pandas were her "number one" reason to visit. "So you know I am a real fan of pandas. I hope China will continue to loan pandas to us."