Suu Kyi has been in detention since February 2021 when an elected civilian government led by her was ousted by Myanmar's military in a dawn coup, plunging the impoverished Southeast Asian nation into turmoil.
Since then, Suu Kyi's exact whereabouts and health condition have been difficult to determine, with no foreign leader or envoy having publicly met her despite requests for contact from countries in the region that have excluded Myanmar's leadership from their summits.
On Monday, Suu Kyi met with Arnaud de Baecque, Resident Representative of the International Committee of the Red Cross to Myanmar in the capital Naypyitaw, government spokesperson Khine Khine Soe said in a message via Telegram.
The ICRC confirmed a delegate had met with Suu Kyi, without naming the official, while her son described the visit as the first positive development concerning his mother in more than five years.
In one of four photographs provided by the Myanmar government spokesperson, Suu Kyi is seen dressed in traditional Burmese attire and standing unaided, shaking hands with Baecque.
In another, they are sat in a sparsely furnished, wood-panelled room containing only two chairs and a desk.
The ICRC said the visit had met with its standards and procedures for visiting people deprived of liberty.
"This included the opportunity to speak with Daw Aung San Suu Kyi in private," it said in a statement, using a Burmese honorific.
Suu Kyi's son, Kim Aris, said he had not yet received independent confirmation of his mother's condition or well-being.
"This may be a first step, but it must not be the last," he said in a statement.
"I hope this leads to further humanitarian progress, including direct contact with my mother, access for our family, credible and independently verified information about her well-being, and ultimately her immediate and unconditional release, together with all political prisoners."
Aris told Reuters in December that he had received only sporadic, second-hand details about his mother's heart, bone and gum problems -- and had not heard from her in years.
After a marathon run of secret trials following the 2021 coup, Suu Kyi -- who was held under house arrest for a total of 15 years under a previous junta -- was sentenced to 33 years' detention, convicted of charges ranging from corruption and inciting election fraud to violating state secrecy rules.
Her allies maintain the charges were politically motivated and aimed at sidelining the most popular politician in the country of 51 million people.
The sentence was later reduced, most recently in April, leaving her with 18 years still to serve, according to a member of her legal team.
Myanmar's military-backed administrations have repeatedly claimed Suu Kyi -- daughter of the country's independence hero General Aung San -- is in "good health", even as international pressure has grown to allow independent verification.
After a meeting between Myanmar's foreign minister and counterparts from the regional ASEAN bloc last month, Thailand's top diplomat Sihasak Phuangketkeow called for access to Suu Kyi to verify her health.
ASEAN has barred Myanmar's leadership from its top meetings for failure to implement a peace roadmap.
In another released photo, offering a rare glimpse inside what appears to be her residence, Suu Kyi is seen cutting a birthday cake inscribed with her name, with a clothes rack and storage boxes visible in the background.
A fourth photograph is a close-up of the cake, inscribed with "Happy Birthday Aunty Suu 29.6.2026".
Reuters was not able to independently verify the location and the date when the pictures were taken. No earlier version of the pictures was found posted online before Monday.