Conditions in Myanmar's crisis-hit northern Rakhine state are "not conducive" to bringing back Rohingya from Bangladesh, the UN told AFP, in remarks that jar with the country's insistence that it is ready for returnees.
Some 700,000 Rohingya Muslims have fled over the border since August to escape a bloody military crackdown that has left a trail of torched villages in its wake as refugees allege murder and rape by Myanmar's armed forces.
The army denies the allegations and casts its campaign as a legitimate response to Rohingya militant attacks on August 25 that killed about a dozen border guard police.
Myanmar and Bangladesh signed a repatriation deal in November but not one refugee has returned.
"Right now, the conditions are not conducive to a voluntary, dignified and sustainable return," said Ursula Mueller, assistant secretary general for the UN's Office for the Coordination of Humanitarian Affairs.
Speaking to AFP at the end of a six-day trip to the country during which she visited northern Rakhine, Mueller said Myanmar needs to address "critical issues of freedom of movement, social cohesion, livelihoods, and access to services".
For years members of the stateless Muslim minority have been deemed immigrants from Bangladesh, forced to live under apartheid-like conditions with severe restrictions on their movement and limited options for education and healthcare.
Myanmar has repeatedly said it has completed the groundwork to accept back Rohingya refugees.
"We are ready. The buildings are ready. The hospital and clinics are ready," Aung Tun Thet, chief coordinator of a government-backed organisation working on resettlement in Rakhine, told state media this week.
"We have done what we can. If they don't feel safe then there isn't anything we can do."
During her trip, Mueller also spoke to Rohingya Muslims who have been confined in "deplorable" camps and settlements within Rakhine since a previous wave of inter-communal violence six years ago.
"We cannot, and must not, forget the plight of over 400,000 Muslim people still living in Rakhine state who continue to face a life of hardship and marginalisation due to movement restrictions," she said.