A baby giant panda has died in a Tokyo zoo less than a week after it became the first panda to be born in the country in 24 years.

Ueno Zoo said the unnamed male cub died from pneumonia. It was initially reported as healthy but its condition deteriorated and it was placed in an incubator.

The panda was returned to its mother but keepers later noticed the cub was not breathing. After massaging its heart, the keepers declared the baby panda dead an hour later.

Yutaka Fukuda, the chief panda keeper, said that traces of milk had been found in the baby's bronchial tube, after milk had accidently entered the its airway during breastfeeding.

"They peacefully spent the night and the baby was doing fine just this morning. It happened so suddenly, and it's such a pity," said Fukuda.

Baby panda dies in Tokyo Zoo
A tragic end for the first giant panda born in Japan in 24 years (Reuters)

The IB Times reported the birth as the first at Ueno Zoo in 24 years. The parents, mother Shin Shin and father Ri Ri, had both been shipped over to Japan just after the devastating tsunami hit the country in March 2011.

The fact that the panda had been conceived naturally was unusual as panda reproduction is notoriously difficult. The standard procedure across zoos worldwide is to impregnate female panda's through artificial insemination.

The Ueno birth created a great deal of excitement across Japan and many Japanese are in mourning. Zoo management said a space would be set up for visitors to lay flowers and pray for the dead panda.