CALGARY -- A pair of giant panda cubs at the Calgary Zoo will be remaining in Canada longer than anticipated.

Jia Panpan and Jia Yueyue were born in Toronto in 2015 at the Toronto Zoo, and were transferred to Calgary with their parents in March of last year.

The panda parents are on loan from China as part of a 10-year agreement and will stay in Calgary until 2023, but the cubs are being transferred to China and the zoo already held a farewell celebration earlier this month.

On Monday, however, the zoo posted on Facebook that the cubs' stay has been extended until early 2020.

Spokeswoman Alison Archambault explains that "international permitting and air transport challenges" are the reason for the delay.

In China, the cubs will go to a breeding program facility in Chengdu.

This report by The Canadian Press was first published Oct. 28, 2019.