BANGKOK — Myanmar’ s detained former leader Aung San Suu Kyi on Thursday was allowed her first telephone call in more than five years with her son, Kim Aris, who announced the occasion on his Facebook page.

Suu Kyi has been in detention since a February 2021 army takeover ousted her elected government. She is currently serving an 18-year prison sentence under house arrest after being convicted on charges that her supporters and rights groups have said are politically motivated.

“Today, I was finally able to speak with my mother, Daw Aung San Suu Kyi, after more than five years,” Aris wrote on Facebook. “Hearing her voice again means more than words can express.”Soe, the spokesperson for Myanmar President Min Aung Hlaing, confirmed on the Telegram messaging platform that Aris held a 20-minute conversation with his mother, who is under house arrest at an undisclosed location in the capital Naypyitaw. Aris spoke from the Myanmar Embassy in London.

Aris, who is Suu Kyi’s younger son and lives in London, had waged an online campaign with other Myanmar democracy activists to demand evidence that his mother is alive and well. She has not been seen publicly since the 2021 takeover, and her whereabouts and condition have been largely kept from public view.

In August, a representative of the International Committee of the Red Cross visited Suu Kyi, her first known contact with an outside independent international humanitarian organization since her detention in February 2021.

Aris noted Thursday that Suu Kyi is 81 and “unjustly detained,” and urged her supporters to “keep speaking up until she is free.”“My mother and all political prisoners must be released immediately and unconditionally. Freedom is not negotiable,” he wrote. Kim is one of two sons that Suu Kyi had with her late husband, British academic Michael Aris.

Min Aung Hlaing, who led the military’s 2021 seizure of power, has been seeking to end Myanmar’s international isolation, imposed after Suu Kyi was ousted and imprisoned, trying to project a return to normalcy after holding an election at the beginning of this year.

Although the election was judged by critics to be neither free nor fair, and meant to entrench the military’s grip on power, Min Aung Hlaing’s government seems to be making progress in restoring warmer relations with neighboring countries and even the United States, one of the fiercest critics of the regime and a major driver of international sanctions. Meanwhile, its military continues to wage a fierce war against pro-democracy guerrillas and ethnic rebel groups.

On Monday, Myanmar’s military-backed government said it had delivered two books sent by Britain’s King Charles III to Suu Kyi, along with a sealed envelope and diplomatic correspondence. Its announcement of that event and Thursday’s phone call appear to be part of a charm offensive aimed at building diplomatic legitimacy.

The international community, including Myanmar’s fellow members of the Association of Southeast Asian Nations , has called for Suu Kyi’s release and access to or engagement with Suu Kyi as part of efforts to resolve the country’s political crisis, but the government has rejected the calls.