[1/2] Rohingya refugees rescued by fishermen are seen on a boat behind a patrol boat near the coast of Seunuddon beach in North Aceh, Indonesia, June 24, 2020.
In Buddhist-majority Myanmar, most Rohingya are denied citizenship and are seen as illegal immigrants from South Asia.
Nearly 200 Rohingya are feared dead or missing at sea this year already.
"We hope against hope that the 180 missing are still alive somewhere out there", said UNHCR spokesperson Babar Baloch.
Two boats carrying a total of 230 Rohingya refugees, including women and children, landed on the shores of Indonesia's Aceh province in November, while this month, Sri Lanka's navy rescued 104 Rohingya adrift off the Indian Ocean island's northern coast.