Researchers from China and Russia have for the first time determined the population of the endangered Amur leopard, which lives along the border of the two countries.

A joint operation this year found that at least 80 adult Amur leopards were living in China's Hunchun, Wangqing and Laoyeling nature reserves and surrounding areas, as well as the far east of Russia, the Chinese research team announced on Monday.

The project was conducted by a Chinese team along with Beijing Normal University and a Russian leopard park.

The border area is believed to be the only area in the world where Amur leopards, the world's most endangered feline, live.

The findings exceed previous estimations. Surveys in the early 21th century put the population at between 25 and 35, said Ge Jianping from the university.

The team also discovered that an isolated group of Siberian tigers, around 38, lived in the border area.

"The findings show that the populations of Amur leopards and Siberian tigers are in a stage of rapid expansion. It reflects the remarkable protective progress on behalf of the two countries," Ge said.

Ge said the Chinese team had signed an agreement with the Russian park to monitor the two species.