Almost two months after the Rohingya crisis began, nearly 600,000 people have fled the military-led violence, and still more are on the way.

Key points: UN set to plead for additional urgent assistance

UN set to plead for additional urgent assistance World Food Program will get some of additional $10 million in Australian aid

World Food Program will get some of additional $10 million in Australian aid Lessons can be learnt from countries that have hosted significant refugee populations

Australia has pledged a further $10 million, but one decorated Australian nurse says it's impossible to calculate what may ultimately be needed, describing the situation the worst she's ever seen.

The plight of Rohingya refugees may have slid from many Australians' minds, but Libby Bowell is confronting it daily.

"To be truthful, this is the worst thing I've ever seen," she told the ABC from Bangladesh.

The Australian nurse and Red Cross worker speaks from experience.

In 2015, Ms Bowell was given the Florence Nightingale humanitarian award for her work on Africa's Ebola crisis.

Witnessing the torment inside refugee camps

Confounding her and many other disaster veterans, is the ceaseless stream of Rohingya refugees coming from Myanmar, arriving into cramped and difficult conditions in the swelling camps.

"We get this false lull that we had just before the 15,000 came [last week]," she said.

"I actually went down to the border and had a look, and just saw the aerial shots that are around now, and just thought, oh my god."

Sorry, this video has expired UNHCR drone footage shows the Rohingyas fleeing Myanmar into Bangladesh.

Ms Bowell describes in haunting terms the difficulty of seeing babies and the elderly dying of thirst in the tropical heat.

"I've never seen so many malnourished little babies and children and old women, and soulless women," she said.

"I've seen, just, death behind their eyes. That's probably what's sticking with me at the moment, because I saw that just over, and over, and over again two days ago."

The problems of so many in such little space are manifest.

Attempts to dig wells for clean water have so far yielded insufficient supply, exacerbating aid agencies' biggest fear — cholera.

Libby Bowell describes the difficulty of seeing babies and elderly dying of thirst. ( Supplied: Angela Hill/IFRC )

UN to plead for urgent assistance

In Switzerland, the UN is due to plead for additional urgent assistance.

The World Food Program's Michael Dunford said because the number of people needing help was still increasing, so too were the aid demands.

"WFP has already fed 580,000 refugees. Just yesterday we fed an additional 10,000 as they came across the border," he said.

"But we are still scaling up. We still need to reach up to a million people. We've received strong support from our donors but we need an additional $US54 million to get us through until the end of February if we are able to reach our targets."

Rohingya refugees gather to receive health care at a Bangladeshi camp. ( Supplied: Angela Hill/IFRC )

The WFP will get some of an additional $10 million in Australian aid which Foreign Minister Julie Bishop has announced.

"Australian support will go towards providing food, clean water, shelter and essential health services," a statement from the minister's office said.

"Our assistance will also help treat children for malnutrition, create safe and secure areas for vulnerable women and provide maternal health services."

Other charities to benefit are Oxfam, Save the Children and Care, who are also running public appeals.

Both have expressed particular concern for women and children.

Women and children are most at risk in Bangladesh's refugee camps. ( Supplied: UNICEF, file )

Bangladesh faces burden it can't bear alone

Save the Children's Mat Tinkler has just returned from Bangladesh, and says it's also imperative to look beyond food and shelter.

The challenge, he says, is understandable concern in Bangladesh — that one of the world's poorest countries is facing a long-term burden it simply cannot bear alone.

We need to learn from places such as Jordan, Lebanon and Turkey that have hosted significant refugee populations fleeing Syria for many years.

"In that scenario, we probably took too long to set up a medium and longer term response to this crisis, and we need to make sure we don't make the same mistake here," Mr Tinkler said.

With no end in sight, the Red Cross's Ms Bowell agreed.

"I wish I could say I could see it getting better," she said.

"But when we've still a couple of hundred thousand [Rohingya] on the other side of the border, that's still a way off."

This week will mark two months since August 25, when Rohingya insurgent attacks on security posts triggered a vicious counter-offensive by the Myanmar army.

There are allegations the military is starving-out the remaining Rohingya by laying siege to their villages.

But exactly what is happening inside Rakhine state is difficult to ascertain, because Myanmar has continued to resist calls for improved humanitarian access.