ntao's offer of two pandas, saying the crowd-pleasing animals would be miserable in a zoo. Hu, trying to reconcile with Japan on the first visit by a Chinese president to Tokyo in a decade, offered to lend a male and a female panda to replace Ling Ling, who died last week at Tokyo's Ueno Zoo.
People for the Ethical Treatment of Animals (PETA) sent a letter to Foreign Minister Masahiko Komura urging Japan to halt the deal.
The US-based rights group noted that the pandas were being leased, not gifted, and estimated the zoo would pay China around one million dollars a year for each animal.
"Pandas are an endangered species, not a commodity to be traded for human amusement," PETA campaigner Rie Ichikawa said in the letter.
"In honor of the late Ling Ling -- the panda who spent his entire life in a zoo, where he was denied his freedom, the right to choose his own mate, and everything that was natural and important to him -- we urge Minister Komura to declare that no more pandas will be taken from their homes and sentenced to a life at the Ueno Zoo."
Ling Ling died of heart failure last week at the age of 22 -- the equivalent of 70 in human years. Zoo Keepers tried but failed to encourage Ling Ling to mate with visiting pandas.
China has long pursued "panda diplomacy," lending or gifting the cuddly but endangered bears as a way to improve relations.
Ling Ling was the only giant panda holding Japanese "nationality." Another eight pandas are in Japan but all are leased by Chinese authorities.
Taiwan in 2006 rejected two pandas from mainland China, saying they would be better off in their natural habitat, but there was wide speculation that political factors were at play.
