The two giant pandas, Huan Huan and Yuan Zai, play at the Beauval Zoo in Saint-Aignan, central France, Feb. 18, 2012. (Xinhua/Tang Ji)

PARIS, July 27 (Xinhua) -- Giant panda Huan Huan, which is on loan to France from China, is pregnant and likely to give birth to the first French cub in early August, Beauval zoo announced Wednesday.

Ultrasound tests on the female giant panda detected "a small heart beating" and a fetus at 3.4 cm.

After a 50-day gestation period, the new comer is expected on either August 4 or 5. It will likely weight just 100 grammes, according to a statement of the zoo.

The female panda and her male partner Yuan Zi arrived in central France's Beauval zoo in January 2012.

"It is a very good news. We are very happy. Everything is ready for birth, and it takes two or three months for the baby to be visible," said Delphine Delord, the zoo communication director.

"In February, we had an artificial insemination," she added.

The female panda is only on heat once a year for two days.

There are about 2,000 pandas in the world. They are classified as "vulnerable" species by the International Union for Conservation of Nature (IUCN).