Giant panda twins Meilun and Meihuan set off on Thursday and will arrive in Chengdu in southwest China's Sichuan Province two days later, said Zoo Atlanta.

Panda twins Meilun and Meihuan in Zoo Atlanta. [Photo: Xinhua]

The zoo also has prepared 170 kilograms of bamboos for the three-year-old twins.

The 3-year-old giant panda twins, daughters of the first giant panda couple in the zoo Lunlun and Yangyang, are the first surviving giant panda twins in the US. Lunlun and Yangyang have been on loan from China.

Since their births, the twins have been the most popular animals in the zoo. Their names were selected through an online vote by locals.

According to an agreement reached by China and the US, panda cubs born in the US to parents on loan from China are to be returned to China before turning four years old. They are then taken to participate in breeding projects in China.

The National Zoological Park in Washington D.C. has also announced it will send their cub Baobao back to China next year.