The Smithsonian’s National Zoo and Conservation Biology Institute in Washington, D.C., announced that two giant pandas, Bao Li and Qing Boa, are set to arrive from China this Tuesday.

Bao Li is a descendant of Bao Bao, a panda born at the zoo in 2013.

The National Zoo participates in a breeding program aimed at conserving the vulnerable species, which involves returning pandas born there to China at age four.

This follows the recent arrival of pandas in the U.S. after a 21-year hiatus, signaling a renewed partnership between the U.S. and China in panda conservation, ABC News has reported.

The exact arrival time has not been disclosed for safety reasons.

Written by B.C. Begley