The United States and the influential bloc of Southeast Asian nations have issued separate statements demanding the unconditional release of detained Burmese leader Aung San Suu Kyi.

The statements were issued days after Ms Suu Kyi held her first meeting with a foreign official in more than five years since she was ousted from power and detained in a 2021 coup.

Both the US and the Philippines, which chairs the 11-member Association of Southeast Asian Nations (Asean) this year, called for the immediate release of Ms Suu Kyi and everyone else detained since the military seized power, while welcoming Ms Suu Kyi’s visit from a Red Cross official earlier this week.

"We urge the further expansion of access to persons held in detention in Myanmar since February 2021, and reiterate our call for their release, including Daw Aung San Suu Kyi's complete and unconditional release," the Asean chair said in its statement, using the Burmese honorific for an older woman.

The bloc said it hoped the visit would open the way for regular and sustained access to Ms Suu Kyi for her family, her lawyers, doctors and humanitarian organisations, and described it as a positive step towards dialogue and reconciliation between all sides in Myanmar. It said it viewed the meeting as part of Myanmar's efforts towards peace and reconciliation.

In a separate statement posted on X by the US embassy in Myanmar and released via the state department, Washington called for her "immediate and unconditional release".

"We hope this visit marks the beginning of regular humanitarian access to Aung San Suu Kyi and serves as a pathway to greater access to all political prisoners," it said, adding a call for the authorities to guarantee her medical care and visits, for the release of everyone unjustly detained, and for the military to enter talks with all groups to end the war that followed the coup.

Photographs published by the Myanmar president's office on Monday showed Ms Suu Kyi, now 81, shaking hands with Arnaud de Baecque, the Red Cross's head of delegation in Myanmar, at a meeting in the capital Naypyidaw. Another shows her cutting a birthday cake bearing the words "Happy Birthday Aunty Suu".

They are the first independently verifiable images of Ms Suu Kyi to be published since the army deposed her government in February 2021, and the meeting is the first publicised contact between her and any foreign official in that time.

Her son, Kim Aris, a British national who has campaigned for her release, called the visit the first positive development concerning his mother in more than five years but said he had still received no independent confirmation of her condition.

"This may be a first step, but it must not be the last," he said in a statement.

“I feel relief to see proof that she is alive: I feel anger that she is being unjustly held and has been in solitary confinement for more than five years damaging her mental and physical health,” he told The Independent.

Ms Suu Kyi, who won the Nobel peace prize in 1991 for her opposition to a previous generation of Myanmar's generals, was jailed after the coup on a series of charges that rights groups say were invented to remove her and her National League for Democracy party from politics. Neither the location of her detention nor how much of her sentence remains has been disclosed.

She was moved from prison to house arrest in April, after Min Aung Hlaing, the general who led the coup, commuted the rest of her sentence. He was installed as civilian president the same month following elections that have widely been dismissed as a sham.

The 2021 coup triggered a civil war that has killed more than 100,000 people, according to the Armed Conflict Location and Event Data Project, which tracks political violence.

The timing of the Red Cross visit has drawn attention because it came days before Min Aung Hlaing was due in Bangkok on an official visit. He has already travelled to India, China and Laos since becoming president, as Myanmar attempts to end the diplomatic isolation imposed after the coup.

"It's the old military game plan to use Suu Kyi as a bargaining chip," David Mathieson, an independent analyst on Myanmar, told AFP, saying the timing was no coincidence and describing the visit as the card Min Aung Hlaing had been holding back as a gesture to the outside world.

The Asean bloc has barred Myanmar's leadership from its summits since the coup, though Thailand has been pressing for the country's return. The chair's statement on Friday said it hoped Asean's special envoy would be allowed into Myanmar to meet all parties, including Ms Suu Kyi, access the junta has so far refused.