Wild tigers could be returning to Kazakhstan after a groundbreaking reintroduction plan was signed off Friday.

Seven decades since poaching and habitat destruction wiped out indigenous stocks of the giant cats, it is hoped they will once again roam free -- but experts said it will take years.

The Central Asian country's agreement with the World Wildlife Fund requires it to gradually integrate Amur tigers, closely related to the extinct Caspian tiger, that disappeared from its southeastern Ili-Balkhash region in the mid-20th century.

The fund is providing $10 million (8.3 million euros) for the project that will see Kazakhstan become the first country to reintroduce a population of large cats back into a territory following an extinction.

WWF's Russian representative Igor Chestin hailed the signing as a "event of global significance" but warned reintroducing tigers into the country will take "years".

"It will be years before tigers appear on this territory because the territory needs to be specially prepared," Chestin said at a press conference in the Kazakh capital Astana.

Kazakh Agriculture Minister Askar Myrzakhmetov said work on a specially protected natural area for the tigers would start at the beginning of next year.

"In fact, we are talking about restoring a whole ecosystem, where this species is set to be reintroduced," Myrzakhmetov said at the press conference.

According to a scientific article on the introduction, co-authored by the WWF's Chestin, Caspian tigers inhabited a range taking in 13 modern-day countries with Turkey and China at its extremes just prior to the turn of the century.

The Soviet Union sped up the animal's extinction with mass irrigation and agricultural development that cut into the partly wooded habitat it inhabited along with its prey, mainly boar and deer.

Bounty hunting was also rife in the early Soviet period.

The Caspian tiger is generally thought to have become extinct globally in the mid to late 20th century.

Numbers of wild tigers as a whole have dwindled precipitously over the last century, plunging from 100,000 to fewer than 4,000 across a dozen countries today.

In 2016 tigers were declared "functionally extinct" by the WWF in Cambodia, with the last big cat seen on a camera trap there in 2007.