There is no Rohingya amongst Myanmar's ethnicities.
During a press conference at Lancaster house in London on Thursday, Tillerson stressed that the violence against the Rohingya, a stateless Muslim minority group, must stop.
US Deputy Assistant Secretary of State Patrick Murphy is expected to travel to Myanmar in the coming days for discussions on the crisis, after summoning Myanmar's ambassador to express US concerns on Wednesday. It has realised that the situation, which has been described as a "typical textbook ethnic cleansing" by the United Nations, merits dispatch of a senior-level state department official to that country.
Earlier on Thursday the European Parliament passed a resolution calling on the "military and security forces in Myanmar to immediately cease the killings, harassment, and rape of the Rohingya people, and the burning of their homes".
During that meeting, Murphy told the ambassador that Myanmar should publicly acknowledge that Rohingya groups in particular have fled across the border into Bangladesh, a senior State Department official familiar with the conversation told CNN, and that those refugees should now be allowed to return home.
Britain and the United States have issued their clearest call yet for the Myanmar Government to step in and stop what the United Nations calls an "ethnic cleansing" operation in the country's west.
An estimated 380,000 Rohingya refugees have fled the violence in Myanmar and are now seeking refuge in Bangladesh, UN Secretary General António Guterres said Wednesday.
Global pressure on Myanmar heightened this week after United Nations rights chief Zeid Ra'ad Al Hussein said the violence seemed to be a "textbook example of ethnic cleansing". Observers say the violence is being carried out by the Burmese military.
Combined with the Rohingyas who fled during the last round of violence in Rakhine state last October, Dujarric said "it's estimated that some 40 per cent of the total Rohingya population have now fled into Bangladesh".