Burma's de facto leader Aung San Suu Kyi acknowledged that Theresa May must be "extremely busy" following the Brexit vote as she began talks with the Prime Minister at Downing Street.
Mrs May said there was "certainly a lot to do" after congratulating the Nobel Peace Prize laureate for helping to lead Burma's transition to a civilian government.
Ms Suu Kyi said she was "glad to be" at No10 as the pair began discussions expected to focus bilateral relations between the two countries and what the UK can do to help with Burma's reconciliation process as well as its democracy and respect for human rights.
Ms Suu Kyi, whose National League for Democracy party swept to victory in 2015 elections, endured years of house arrest and harassment by military rulers while continuing her non-violent campaign to unseat them and usher in the first civilian government in more than five decades.
She holds the country's specially created post of state counsellor - her two sons' British citizenship prohibiting her from becoming president because of the country's military-era constitution.
Mrs May could raise the plight of the Rohingya Muslims in Burma, who have suffered institutional discrimination by the authorities and in wider society.
The issue was raised with Ms Suu Kyi yesterday by Foreign Secretary Boris Johnson, who welcomed the establishment of the Rakhine Commission, led by Kofi Annan, to tackle the situation facing the Rohingya community.
Amnesty UK urged Mrs May to raise Burma's human rights problems with Ms Suu Kyi, including the plight of the Rohingya.
Polly Truscott, Amnesty UK's foreign affairs adviser, said: "It's great to see Aung San Suu Kyi here on a state visit.
"Amnesty campaigned for her release for so long and it's hugely gratifying that she's free to take her position in the Burmese parliament and on the international stage.
"As well as welcoming her guest, Theresa May should be using this visit to raise important human rights problems with Aung San Suu Kyi, including the urgent need to provide proper protection to Burma's Rohingya people who face horrific persecution.
"The Burmese government's failure to address their suffering is a stain on its international reputation."