By Ruma Paul

DHAKA (Reuters) - Bangladesh is determined to relocate Rohingya Muslims fleeing violence in Myanmar to a Bay of Bengal island that critics say is unliveable, a Bangladeshi minister said, adding that the move is temporary and Myanmar will ultimately have to take them back.

Around 69,000 people have fled the Muslim-majority northern part of Rakhine State to Bangladesh since the Myanmar military launched a security operation in response to attacks on police border posts on Oct. 9. Scores of people have been killed.

Bangladesh last month revived a much-criticized 2015 plan to move new and old refugees from Myanmar to the island of Thengar Char - which floods at high tide - surprising aid groups who were not consulted and consider the relocation impracticable.

Shahriar Alam, Bangladesh's junior foreign affairs minister, said the refugees would be moved gradually after Thengar Char was developed with "shelters and other facilities". There was, however, no timeframe on when the move would start, he said.

"After considering all aspects, we have taken a firm decision to shift them to the island. Still, this is a very early stage of our decision," he told Reuters by phone.

"We also have plans to provide them poultry or livestock for their livelihood. But all these arrangements are temporary. Myanmar will have to take them back."

The plight of the stateless Rohingya, of whom there are some 1.1 million living in apartheid-like conditions Rakhine, has long been a source of friction between Myanmar and Bangladesh.

Many in mostly Buddhist Myanmar refer to them as "Bengalis" - denoting that they are considered illegal immigrants from Bangladesh - and they are denied citizenship despite some tracing their lineage in the country back for generations.

Officials in Bangladesh, where the Rohingya are also not accepted, refer to "Muslim nationals of Myanmar".

DELUGED AT HIGH TIDE

A government official at the Bangladesh municipality under which Thengar Char comes said the island was isolated and gets deluged at high tide, but the government could build embankments to make it liveable. He declined to be named.

Alam said Bangladesh would also develop existing camps around Cox's Bazar, near the border, and expects financial support from outside.

"They are living in inhumane conditions," he said.

About 30,000 people live in official camps run by the United Nations High Commissioner for Refugees, while tens of thousands more, including the new arrivals, are settled in makeshift settlements built around the camps and in the Cox's Bazar area.

Experts estimate there are between 200,000 and 500,000 undocumented Rohingya in Bangladesh.

Dhaka said in a Jan. 26 notice that further mixing of the refugees with Bangladeshi citizens could lead to "law and order issues" and the spread of communicable diseases.

Alam said Bangladesh was trying to improve the living conditions of the refugees, but that it was important for Myanmar to take them back soon because Cox's Bazar's "social condition was deteriorating from the influx".

"Taking the Rohingya back and giving them citizenship is the only solution to the crisis," Alam said. "They are getting involved in drugs and other unlawful activities. If we could have confined them in the camp, it would not have happened."

REPATRIATION TALKS

Myanmar has said it has agreed to talk about repatriation, but only for those who have crossed the border since Oct. 9.

"The people that Bangladesh is saying are on their side, we have to verify that they are from Myanmar. We can't just accept on face value if they say they are from Myanmar," Aye Aye Soe, deputy director of Myanmar's Ministry of Foreign Affairs, told Reuters on Wednesday.

"If they are found to be from Myanmar, we will take them back and of course we will do that in due time," she said, adding that the situation in northern Rakhine had to return to "normalcy" before any repatriation could begin.

On citizenship, Aye Aye Soe said the administration of Nobel Peace Prize winner Aung San Suu Kyi had attempted to start a verification process in April, but had faced resistance from local community leaders who insist on being recognized as "Rohingya", a term Myanmar rejects.

"We are going to push this process forward again," she said.

(Reporting by Ruma Paul in DHAKA; Additional reporting by Simon Lewis in YANGON and Antoni Slodkowski in COX'S BAZAR; Writing by Krishna N. Das; Editing by Alex Richardson)