Burmese leader Aung Sang Suu Kyi's Nobel Peace Prize cannot be revoked in the row over the treatment of Rohingya Muslims, the Norwegian Nobel Institute has said.
An online petition signed by more than 386,000 people on Change.org is calling for Ms Suu Kyi to be stripped of her award over the persecution of Burma's Rohingya community.
The institute said neither the will of prize founder Alfred Nobel nor the Nobel Foundation's rules provide for the possibility of withdrawing the honour from laureates.
She received the award in 1991 for "her non-violent struggle for democracy and human rights" while standing up against military rulers.
She became the country's de facto leader after Burma held its first free election in 2012 and she led her party to a landslide victory.
Discussing the Rohingya situation on Thursday, she said: "I think it's a little unreasonable to expect us to resolve everything in 18 months. As you know that we have all been in the administration only 18 months.
"We're trying to progress as quickly as possible on the development front, because one of the biggest problems is the matter of very limited resources."
Another Nobel Peace Prize winner, Malala Yousafzai, pressed Ms Suu Kyi to act, saying: "Every time I see the news, my heart breaks at the suffering of the Rohingya Muslims in Myanmar (Burma).
"Over the last several years, I have repeatedly condemned this tragic and shameful treatment. I am still waiting for my fellow Nobel Laureate Aung San Suu Kyi to do the same. The world is waiting and the Rohingya Muslims are waiting."
On Thursday, former South African archbishop Desmond Tutu urged Ms Suu Kyi to intervene to stop the persecution of the Rohingya.
In an open letter, he told his fellow Nobel Peace Prize winner that it is "incongruous for a symbol of righteousness" to lead a country where violence against the Rohingya is being carried out.
Rohingya have described large-scale violence perpetrated by Burmese troops and Buddhist mobs - setting fire to their homes, spraying bullets indiscriminately and ordering them to leave or be killed.
Ms Suu Kyi has dismissed the Rohingya crisis as a misinformation campaign.