PRETORIA, South Africa – South Africa's Cabinet has approved the relocation of ­rhinos from the country's Kruger National Park to secret sites both within in the country and across its borders to combat a surge in poaching.

Discussions with Botswana and Zambia have started, Edna Molewa, the country's minister of environmental affairs, said Tuesday.

South Africa, home to most of the world's rhinos, is struggling to protect the pachyderms against poachers, many of whom stream across the border between Mozambique and Kruger armed with automatic rifles and night sights.

So far this year, 638 rhinos have been poached in South Africa, almost two-thirds of those in Kruger, compared with 1,004 in all of 2013.

"South Africa also recognizes international opportunities for establishing rhino strongholds in neighboring countries," Molewa said.

Poaching has surged in South African game reserves and private game ranches and beyond as demand for the animals' horns climbs in Asian nations including China and Vietnam because of a false belief that they cure diseases.

As many as 500 rhinos could be safely moved from Kruger, a reserve the size of Israel, said Sam Ferreira, a large mammal ecologist at South African National Parks. Moving such a large number would be logistically difficult, he said.

In addition to protecting the animals from poachers, relocations can boost populations as some are moved from areas where there are too many ­rhinos for the ecosystem to support and birthrates are declining, he said.

"The translocations are the backbone of what South Africans have achieved with rhinos" in conservation, ­Ferreira said. About 1,500 ­rhinos were relocated from Kruger between 1997 and 2013, a program that "has contributed significantly" to the growth of the South African population of the animals, Molewa said.

South Africa's government also has taken other steps to protect rhinos, including deploying soldiers in Kruger.