The violence which drove 700,000 Rohingya Muslims from Myanmar into Bangladesh was "without excuse", US Vice President Mike Pence told Aung San Suu Kyi in stinging comments on a summit sidelines on Wednesday.
Suu Kyi has seen her reputation as a rights defender destroyed by her refusal to speak up for the Rohingya, a stateless group reviled in Buddhist-majority Myanmar.
Pence added to the pressure on Suu Kyi, who this week has had an Amnesty International honour revoked and faced sharp words from Malaysia's premier at a usually tame meeting of Southeast nations in Singapore.
Sitting next to Suu Kyi, Pence -- who has joined the summit for bilateral meetings -- condemned the "violence and persecution" against the Rohingya as "without excuse".
Then in a front-on challenge to Myanmar's civilian leader, Pence said he was "anxious to hear about the progress" being made to hold the perpetrators accountable.
A crackdown led by Myanmar's army last year sparked an exodus of the Muslim minority into neighbouring Bangladesh, taking with them accounts of atrocities -- rape, murder and arson of their villages.
UN investigators say the army's actions amounted to genocide.
On Thursday a long-delayed -- and heavily criticised -- plan to repatriate Rohingya was set to begin, despite dire warnings their safety will be in jeopardy if forced to return to Myanmar.
- Jailed journalists -
The Rohingya crisis has decimated Myanmar's reputation among large sections of an international community which has supported its transition from outright military rule.
Suu Kyi has no power over the army, which retains autonomy over all security matters.
But she has come under fire for not doing more to speak out against the generals' excesses.
She has also been criticised for her failure to speak up for two Reuters reporters jailed for seven years for breaching a colonial-era state secrets act after reporting on the extrajudicial killing of 10 Rohingya men during a military crackdown last year.
The sentence prompted a storm of global outcry as an assault on freedom of speech, casting doubt on the direction and depth of Myanmar reforms.
In a stark defence of the verdict, Suu Kyi -- herself once a political prisoner held under house arrest by the former junta -- said the pair were jailed under a fair legal process.
"They were not jailed because they were journalists" but because "the court has decided that they had broken the Official Secrets Act", she said.
Suu Kyi's civilian government had the power to drop the charges.
Reuters have appealed the verdict and have been lobbying for the release of the pair who they say were set up by police and arrested to silence their reporting.
The High Court is likely to take up to five or six months to rule on the appeal, during which time the reporters will remain in Yangon's notorious Insein prison.
After numerous delays, the first significant group of Rohingya -- some 2,000 strong -- is due to return to Myanmar on November 15 as part of a repatriation deal signed with Bangladesh a year ago.
However, the UN and rights groups maintain that conditions for their "safe, dignified and sustainable" return are still not in place.