A UN report into Myanmar's Rohingya crisis has called for the country's commander-in-chief and other generals be tried for genocide.
Findings of a US State Department investigation into Myanmar's Rohingya crisis are "consistent" with those of a report by UN investigators, the US ambassador to the United Nations said.
The report called for Myanmar's commander-in-chief and other generals be tried for genocide.
Addressing the UN Security Council, Nikki Haley said "the world can no longer avoid the difficult truth of what happened."
She did not use the term "genocide" and the State Department has said it had not yet concluded whether it shared the determination of "genocidal intent" that UN report attached to the attacks on Rohingya Muslims.
However, Haley said that of the more than 1000 randomly selected Rohingya Muslims surveyed in the State Department's own report, "fully one fifth" witnessed more than 100 victims being killed or injured. She said 82 per cent had seen a killing, more than half had witnessed sexual violence and 45 per cent had witnessed a rape.
"The report identifies one group as the perpetrator of the overwhelming majority of these crimes: the Burmese military and security forces," Haley said, referring to the US report.
She said the Security Council must hold those responsible for the violence to account and added, "The whole world is watching what we do next and if we will act."
Haley's comments provided the first details of the State Department report compiled from 1024 interviews at refugee camps in Bangladesh and completed in late April.
It remained unclear when US Secretary of State Mike Pompeo planned to issue the full US report, which could have legal implications of committing Washington to stronger punitive measures against Myanmar, particularly if Washington concluded there was genocide.
The findings were originally due to be announced ahead of Monday's UN report but have been held up by internal deliberations.
US State Department spokeswoman Heather Nauert said "genocidal intent" was "a very specific legal designation."
"It is not one that is easily made," she told a regular news briefing on Tuesday.
Critics have accused Washington of an overly cautious response to the Rohingya crisis, but a US official, speaking on condition of anonymity, said that the UN findings could increase pressure for tougher US action.
The release of Monday's UN report marked the first explicit UN call for Myanmar officials to face genocide charges over their campaign against the Rohingya. It said the military carried out mass killings and gang rapes with "genocidal intent" and the commander-in-chief and five generals should be prosecuted.
Also on Tuesday, US Senate Majority Leader Mitch McConnell said Myanmar's civilian leader Aung San Suu Kyi, who Washington has championed as a voice of democratic change, could not be blamed for atrocities as she did not have the powers necessary to stop military actions.
Haley made no mention of Suu Kyi, who the UN investigators said had failed to use her "moral authority" to protect civilians.
Some 700,000 Rohingya have fled the crackdown in Myanmar and most are living in refugee camps in neighbouring Bangladesh.