GENEVA (Reuters) - The U.N. independent investigator into human rights in Myanmar called on Wednesday for stronger international pressure to be exerted on Myanmar’s military commanders after being barred from visiting the country for the rest of her tenure.

Special Rapporteur on the situation of human rights in Myanmar, Yanghee Lee addresses a news conference after her report to the Human Rights Council at the United Nations in Geneva, Switzerland, March 13, 2017. REUTERS/Denis Balibouse

Yanghee Lee, U.N. special rapporteur, had been due to visit in January to assess human rights across Myanmar, including alleged abuses against Rohingya Muslims in Rakhine State.

But Myanmar had told her she was no longer welcome, she said, adding in a statement that this suggested something “terribly awful” was happening in the country.

“From what I see right now I’m not sure if they are feeling pressured. I’m not sure if there is the right kind of pressure placed on the military commanders and the generals,” she later told Reuters by telephone from Seoul.

She said it was alarming that Myanmar was strongly supported by China, which has a veto at the U.N.’s top table in New York. Other countries including the United States and human groups were advocating targeted sanctions on the military, she said.

“It has to work. And I’m sure the world has to find a way to make it work. And I think the United Nations and its member states should really try to persuade China to really act towards the protection of human rights,” she said.

Surveys of Rohingya refugees in Bangladesh by aid agency Medecins Sans Frontieres have shown at least 6,700 Rohingya were killed in Rakhine state in the month after violence flared up on Aug 25, the aid group said last week.

More than 650,000 Rohingya have fled into Bangladesh since Aug. 25, when attacks by Muslim insurgents on the Myanmar security forces triggered a sweeping response by the army and Buddhist vigilantes.

Speaking in Beijing, Chinese Foreign Ministry spokeswoman Hua Chunying said the situation in Rakhine State was an internal affair for Myanmar with its own complex history.

Myanmar and Bangladesh resolving this issue was the only way to go, she told reporters.

The international community should provide constructive help for Myanmar and Bangladesh to resolve the issue rather than complicating it, Hua added.

U.N. High Commissioner for Human Rights Zeid Ra’ad al-Hussein has called the violence “a textbook example of ethnic cleansing” and said he would not be surprised if a court eventually ruled that genocide had taken place.

Lee had planned to use her visit to find out procedures for the return of Rohingya refugees, and to investigate increased fighting in Kachin State and Shan Sate in northern Myanmar, where the military is battling autonomy-seeking ethic minority guerrillas.

Lee, in an earlier statement, said Myanmar’s refusal to cooperate with her was a strong indication that there must be “something terribly awful happening” throughout the country, although the government had repeatedly denied any violations of human rights.

“They have said that they have nothing to hide, but their lack of cooperation with my mandate and the fact-finding mission suggests otherwise,” she said.

She was “puzzled and disappointed”, since Myanmar’s ambassador in Geneva, Htin Lynn, had told the U.N. Human Rights Council only two weeks ago that it would cooperate.

“Now I am being told that this decision to no longer cooperate with me is based on the statement I made after I visited the country in July,” she said.

Htin Lynn did not respond to a request for comment.

Neither Zaw Htay, spokesman for Myanmar government leader Aung San Suu Kyi, nor Kyaw Moe Tun, a spokesman for the ministry of foreign affairs that Suu Kyi heads, were immediately available.