Antonio Guterres (Picture: PA images).
UN's Secretary General has called on Myanmar to resolve the Rohingya crisis.
Antonio Guterres expressed concern over the plight of the 730,000 Muslim refugees from Rakhine state.
He was speaking as he met leaders at the Association of Southeast Asian Nations (ASEAN), of which Myanmar is a member state, in Thailand.
Reports from UN investigators and human rights groups say security forces in Myanmar conducted mass rapes, killings and burnings of Rohingya homes.
This, they say, could amount to charges of ethnic cleansing or genocide.
The Rohingya Muslims fled to Bangladesh in August 2017 after Myanmar's military launched a counter-insurgency offensive against them.
It was a response to an attack by a number of Rohingya militants.
Mr Guterres said Myanmar's government should take responsibility and work towards safely repatriating the refugees.
He added it should take measures "to facilitate dialogue with refugees and pursue confidence-building measures" and "to ensure humanitarian actors have full and unfettered access to areas of return, as well as communities in need".
Humanitarian groups say Myanmar has not made necessary provisions for their return, nor established a system to ensure they receive full human rights.
That is despite a formal agreement with Bangladesh for repatriation.