As the country enters its first days in nearly two decades without foriegn troops on the ground - huge questions remain about what the future holds.

As a leading international aid organisation for children and girls, we hold the grave fear that the horror women and children now face in Afghanistan could go on for years.

Late last week, the world reeled in horror as a suicide bomber attacked one of Kabul's major airports, killing more than 170 people.

As the country descends further into chaos, we know that Australia is able to take immediate steps that would improve the circumstances for thousands caught up in the current danger zone

These include expanding Australia's humanitarian intake to 20,000 visas to those most at risk from the Taliban, granting permanent protection to all people from Afghanistan in Australia and in offshore detention centres on bridging visas and temporary protection visas;and making immediate arrangements to bring the families of refugees from Afghanistan to Australia.

These steps won't solve the immediate humanitarian challenges, but they will make tangible differences for the most vulnerable Afghan people currently caught up in the crisis.

They also provide a pathway for Australia to play a constructive and responsible role against a regime that threatens to undermine decades of hard-won progress for women and girls.

Our call to expand our humanitarian refugee intake has been echoed by Christian leaders across Australia, including the Reverend Tim Costello, who said this week: "Our moral duty is to take as many as we can. We believe that can be 20,000 Afghans as an additional intake because our humanitarian cap was already cut by 5,000 last year to 13,750."

We have reason to believe that the Australian community would welcome this.

Australians are an unbelievably generous people - look at the millions raised in the last week for the UNHCR with the support of Ben Quilty, Mariam Veiszadeh and others. Or the hundreds of facebook posts popping up from individuals offering to support Afghan families with practical support, housing, friendship - just as we did for the Syrian people in 2015.

In a country with a population just more than 38 million, in excess of half the population (including 10 million children) are in urgent need of humanitarian assistance today. It's estimated that hundreds of thousands have already been forced to flee their homes.

We know that suffering and resistance is not new to Afghanistan - it is a country that has endured decades of drawn-out and bloody conflict and endemic poverty, and traditionally reported high infant mortality rates, poor childhood immunisation rates and a disproportionately high percentage of girls denied access to education.

Even before the current turmoil, Afghanistan remained one of the most dangerous places on the planet for women and girls.

Our immediate fear is that Afghan women and girls who have achieved an improved standard of living over the past two decades will now have those advances snatched away from them.

More than one third of Afghan women are subject to domestic violence, while often burdened with domestic and unpaid labour. It is incumbent upon Australia to step up and support Afghan women and girls in their darkest hour, as years of progress threaten to unravel.

Prime Minister Scott Morison has described Australia's current intake of 3000 refugees as "a floor not a ceiling", indicating that he is open to increasing the initial intake. We believe Australia needs to expand this humanitarian intake to 20,000 visas to those most at risk.

We need to increase and fast track this initial intake, while prioritising safety and protection for children, especially girls, and strengthen efforts to meet the urgent humanitarian needs of almost 10 million children in Afghanistan who today are facing an unprecedented humanitarian crisis.

We call on the international community to not look away and to act in solidarity with the girls and women in Afghanistan.

This means in practice upholding all international obligations, including guaranteeing asylum to those in need of such protections, with priority to children, girls and youth or vulnerable women and promoters of human rights.

Susanne Legena is CEO of Plan International Australia, the charity for girls' equality.