Swiss President Alain Berset says the return of Rohingya Muslims who have fled violence in Myanmar must be voluntary.

Berset, who is on a four-day visit to Bangladesh, said after meeting with Prime Minister Sheikh Hasina on Monday that the situation of Rohingya in Bangladesh refugee camps is of great concern.

Berset pledged to provide an additional 12 million francs ($12.9 million) for Rohingya this year.

He is expected to visit Rohingya refugee camps on Tuesday.

More than 680,000 Rohingya Muslims have fled from Buddhist-majority Myanmar since the military launched a crackdown in August. In November, Bangladesh and Myanmar agreed to gradually repatriate them. The returns were scheduled to begin in January, but were delayed by incomplete preparations and concerns that the Rohingya were being forced back.