A team of vets has successfully managed to harvest 10 eggs from the last two surviving female northern white rhinos in Kenya, in an unprecedented procedure.
It is hoped the harvested eggs will be fertilised using frozen sperm from a deceased northern white rhinoceros.
The last male, who was named Sudan, died in March 2018.
The rare rhino has been brought to the brink of extinction by poaching and loss of habitat.
The procedure was a joint effort by Ol Pejeta Conservancy, the Leibniz Institute for Zoo & Wildlife Research (IZW), Dvůr Králové Zoo in the Czech Republic and the Kenya Wildlife Service (KWS).
"We are delighted that this partnership gets us one step closer to prevent extinction of the northern white rhinos," said John Waweru, KWS director general.
"This is particularly touching given the heartbreaking death of Sudan, the last male, who died of old age last year in Kenya."
The two surviving rhinos, a mother and a daughter called Najin and Fatu, live under 24-hour armed guard at Ol Pejeta in central Kenya.
For genetic reasons they are, however, both unable to breed. Any embryos will be implanted into a surrogate southern white rhino in the near future.
The technique for the process has been developed over several years, experts say, but is not without risk.
It remains uncertain if the implanted embryos will result in pregnancy.
Last year, a team removed eggs from female southern rhinos and fertilised them with frozen sperm from a male northern white rhino, to create hybrid embryos.
Rhinos are the second-largest land mammal after elephants. The white rhinoceros consists of two sub-species - the southern white rhino and the much rarer and critically endangered northern white rhino.
Poaching is the primary threat facing all rhino species.
Loss of habitat is the other main threat and conservationists say governmental protection of parks and reserves is now essential.