Prominent human rights lawyer Amal Clooney appealed to Aung San Suu Kyi on Friday over a pardon for two Reuters journalists imprisoned in Myanmar, saying the Nobel laureate held the key to their release.

The two fathers, accused of breaching Myanmar's state secrets law while reporting on a massacre of Rohingyas, were jailed for seven years earlier this month, fueling international outrage.

Clooney said the journalists' families had already submitted a request for their pardon, adding that the president can grant a pardon following consultation with Suu Kyi.

"The government can, if it wants to, end it today," the British-Lebanese lawyer told an event dedicated to press freedom on the sidelines of the United Nations General Assembly.

Earlier this month, Suu Kyi defended the jailing of Wa Lone, 32, and Kyaw Soe Oo, 28, hitting back at global criticism of a trial widely seen as an attempt to muzzle the free press.

"She holds the key, … The key to truth and accountability, and the key to a more democratic and prosperous Myanmar," Clooney said. "History will judge her on her response."

"If you care about press freedom you care about this case ... Without a free press you cannot have democracy because you don't know how to judge what your government's doing," Clooney told Reuters after the event.

Meanwhile, Malaysian Prime Minister Mahathir Mohamad, while giving his address to the UN General Assembly on Friday, criticised the government of Myanmar for its treatment of its Rohingya Muslim minority and accuses the rest of the world of failing to act.

Mahathir asked fellow leaders: "Nations are independent, but does this mean that they have a right to massacre their own people?"