Bangladesh's powerful Home Minister has told the ABC he believes an influx of Rohingya refugees represents a threat to his country, and wants more international help to force Myanmar to accept them back.

Key points: Bangladesh's Home Minister calls Rohingya influx "a great challenge"

Bangladesh's Home Minister calls Rohingya influx "a great challenge" Worried their desperation could lead them to join terrorist groups

Worried their desperation could lead them to join terrorist groups More than 400,000 people from Myanmar have fled into Bangladesh in the past month

In less than a month, Bangladesh has seen more than 400,000 Rohingya Muslims fleeing a military crackdown in Myanmar stream across its border, the largest and fastest mass migration Asia has seen in decades.

Asaduzzaman Khan is responsible for Bangladesh's interior security, and said while Bangladesh feels a strong humanitarian obligation to assist in response to what he called "barbarism" on behalf of Myanmar's security forces, he is worried about the risk of international terror organisations recruiting refugees.

"It'll be our threat in the future. These people left everything," Mr Khan told the ABC, saying that the refugees' desperation made them easy recruits.

"For their survival, they will do anything.

"Anyone can easily purchase them. They can join the international terrorist groups also."

Asked if Bangladesh had any evidence of that occurring, he admitted that security agencies did not, but that it was their "assumption" it was likely.

Rohingya Muslims fleeing violence in Rakhine state have been living in limbo in refugee camps. ( Reuters: Danish Siddiqui )

A humanitarian response, with limits

Mr Khan said the sheer number of refugees seeking shelter were placing great strain on the environment and communities in Teknaf and other areas surround the border.

"It is really a great challenge for us," he said.

"We do not stand this kind of misery, this kind of barbarism," Mr Khan added, explaining what prompted Bangladesh to open its border with Myanmar late last month after Rohingya insurgents' attacks on police posts prompted a severe military crackdown.

The United Nations has termed it "ethnic cleansing".

"We've seen village after village burned. Out of humanity, we opened the border," Mr Khan said.

"We've let them come."

But he rejected the Myanmar Government's claim the Rohingya are "illegal Bengali migrants".

"They are not Bangladeshi people. They've lived in Myanmar for hundreds of years," Mr Khan said.

"We believe Myanmar, in the long run, will take back their citizens."

Mr Khan also acknowledged that Aung San Suu Kyi's promise to accept only refugees "verified" under an earlier process which requires them to produce documents few possess does pose a problem.

The minister said Bangladesh wants countries like Australia to put more pressure on its neighbour.

"We expect the international community, like Australia, America, definitely to pursue this Myanmar Government, to take back their citizens," he said.