A male giant panda gifted by China to Taiwan as a symbol of warmer ties died on Saturday after suffering a spate of seizures, Taipei Zoo said.
"Our medical team has confirmed that Tuan Tuan's heart stopped beating at 13:48 (05:48 GMT)," the zoo said in a short statement that did not state the cause of death.
Earlier on Saturday, a separate statement said the panda's condition was "irreversible" and that he could no longer "live a quality life".
Vets first noticed Tuan Tuan, 18, was ill in August, when he began suffering seizures and appeared increasingly unsteady and lethargic.
Medical scans showed he had a brain lesion and he was placed on anti-seizure medication.
The zoo suspected Tuan Tuan had a brain tumour and he was moved into palliative care last month.
Tuan Tuan and his breeding mate Yuan Yuan were given to Taiwan by Beijing in late 2008, at a time when relations between the two were more cordial.
China views Taiwan as part of its territory and has vowed to one day bring the self-ruled democratic island back into the fold, by force if necessary.
In a nod to that goal, the pandas' names combined mean "reunion" or "unity".
The couple became huge stars in Taiwan and Yuan Yuan has since given birth to two female cubs.
Beijing has long deployed "panda diplomacy" and the gift of Tuan Tuan and Yuan Yuan was a move seen to endorse the presidency of then Beijing-friendly leader Ma Ying-jeou.