The Nobel Laureate met with the heads of the US, British and Australian embassies in Yangon for an hour at a government guest-house, after a request in a letter she wrote to the junta chief, said US embassy spokesman Drake Weisert.
"We can confirm that sanctions were discussed at the meeting. However, we do not want to pre-empt Aung San Suu Kyi's discussions with the authorities by discussing the details of the meeting," Weisert told AFP.
Suu Kyi's correspondence with Senior General Than Shwe, which offered suggestions on getting Western sanctions lifted, marked an easing of her stance after years of advocating punitive measures against the ruling generals.
She wrote the letter soon after Washington unveiled a major policy shift to re-engage the junta, a move her lawyers have said she welcomed.
Her lawyer Nyan Win said on Friday that she "wanted to get the facts and figures on Western sanctions" at the meeting with diplomats.
"The authorities allowing Daw Aung San Suu Kyi's request is good. She is getting what she needs," he added. "Daw" is a term of respect in Myanmar.
"We are hoping that the Senior General and Aung San Suu Kyi will meet soon," Nyan Win said, adding that meeting the diplomats meant she "could get chances" to become more involved in politics.
Andrew Heyn, the first British ambassador to meet Suu Kyi since 2003 and the European Union's representative in the talks, said she was "in remarkable form" and "very, very engaged" on the subject of sanctions.
Regarding dialogue with Myanmar, Heyn told the BBC's Today programme: "The full position won't become clear for a while but certainly this is an issue that will be discussed in Brussels with a matter of urgency."
A statement from Australia's department of foreign affairs and trade said the meeting was a "positive step by both the Burmese authorities and Aung San Suu Kyi". Burma is Myanmar's former name.
"The government hopes that this constructive meeting may lay the groundwork for further contact," the Australian statement said, adding that Myanmar officials were present at the talks.
In the past week, Suu Kyi has also had two meetings with minister Aung Kyi, the official liaison between herself and the junta -- the first time they have met for talks since January 2008.
State media reported Sunday that they discussed her letter at the first meeting, but further details of the talks have not yet emerged.
Last week Suu Kyi's appeal against her extended house arrest was rejected by judges, who upheld her August conviction over an incident in which an American man swam uninvited to her house in May.
The guilty verdict for the frail 64-year-old, who has spent around 14 of the past 20 years in detention, earned her an extra 18 months' house arrest and provoked international outrage.
But following its move towards re-engagement, Washington last week held its highest level talks with Myanmar in nearly a decade.
It also emerged Thursday that a senior Myanmar official -- likely prime minister Thein Sein -- will attend US President Barack Obama's talks next month with Southeast Asian nations in Singapore.
However Washington has warned against lifting sanctions until there is progress towards democracy in Myanmar, which has been under military rule since 1962. America has repeatedly pressed for Suu Kyi's release.
"While we welcome the opportunity to meet with Aung San Suu Kyi, we continue to urge Burmese authorities to release her and all other political prisoners from detention immediately and without condition," Weisert added Friday.
The junta refused to let Suu Kyi take power after the country's last elections in 1990, which her National League for Democracy (NLD) party won by a landslide, leading Western countries to impose sanctions.
Her extended house arrest keeps her off the scene for elections promised by the regime next year, adding to criticism that the polls are a sham designed to legitimise the military regime's grip on power.