A national zoo in Washington says China will send it two giant pandas by the end of the year.

The Smithsonian's National Zoo and Conservation Biology Institute announced on Wednesday that the zoo will welcome a pair of 2-year-old male and female pandas.

The zoo says the male panda, Bao Li, is the grandson of a pair that was returned to China last year after living at the zoo for more than 20 years.

China's ambassador to the US, Xie Feng, said at the zoo's news conference that he is "very glad" to share the news of the "envoys of friendship" flying over the Pacific to deepen the friendly ties between the Chinese and American peoples.

First lady Jill Biden said in a video, "We can't wait to celebrate this historic moment...the pandas are coming back to DC."

In recent years, US zoos have been sending back pandas to China as loan agreements lapsed and were not renewed amid tensions between the two countries. A zoo in the state of Georgia is currently the only one with pandas after the Washington zoo sent back three pandas last November.

US media are reporting that the latest announcement follows increased engagement between Washington and Beijing that has put ties on a steadier footing.