Tillerson said violence against the Rohingya Muslim minority showed “characteristics of crimes against humanity.”
Nyan htoo has now had the enormous organ removed.
The U.N. report estimated some 80,000 children 5 and under are at risk of dying as a result of the country's food crisis.
The Irish singer-activist said he was "sick of what has happened in the last 12 months."
“The time for well-meaning, diplomatic words in this Council has passed," Nikki Haley told the U.N. Security Council.
Independent observers are still largely excluded from the area and have not been able to verify the grave.
More than 400,000 members of the Rohingya minority have fled to Bangladesh amid a harsh crackdown by the country’s military.
Aung San Suu Kyi is scheduled to speak on Tuesday for the first time since the crisis.
Over 400,000 Rohingya have fled into Bangladesh after a military crackdown.
Nearly 90,000 Rohingya have sought refuge in Bangladesh in the past 10 days, fleeing the violence.
Ramzan Kadyrov appealed to Putin for help and condemned the persecution of the Rohingya people.
The Rohingya Muslims are one of the most persecuted ethnic groups in the world.
China conducted joint air and land drills near its unstable border with Myanmar as Beijing stressed national security.
A U.N. report last month said the Myanmar army and police had committed mass killings and gang rapes of Rohingya in a campaign that may amount to crimes against humanity and ethnic cleansing.
Two senior U.N. officials told Reuters the crisis is significantly worse than previously thought.
Police said they found weapons and thousands of the stimulant pills in the monk's car.