SYDNEY - Australia's immigration minister Andrew Giles is reviewing Canberra's response to the humanitarian crisis in Afghanistan a year after the Taliban reassumed control. Campaigners are calling on Australia to grant more visas to refugees seeking to flee the conflict-torn country.

It's been a year since the United States-led alliance left Afghanistan.

Tens of thousands of Afghans have been resettled in the U.S. and Europe.

Australia said earlier this year it would allow the resettlement of 16,500 more refugees from Afghanistan over the next four years.

But the number of Afghan nationals trying to reach Australia far outweighs the number of places available.

Authorities in Canberra have received applications for more than 200,000 Afghan asylum seekers, but almost half are yet to be considered.

Andrew Giles, Australia's immigration minister, has acknowledged that the processing system has been overwhelmed. He has ordered a review into Australia's handling of the asylum crisis.

In a statement, a spokesperson for the Department of Home Affairs said that Australia remained "committed to supporting the Afghan community at this distressing time and asks for patience with visa application processes.

But Josephine Langbien, a senior lawyer at the Human Rights Law Center, an independent rights organization, is demanding Canberra do more.

"The Australian government promised to help the people of Afghanistan, but help is not coming fast enough. We [were] promised additional humanitarian visas, but we know that only a few thousand of those visas have actually been issued."

Australia has been granting around 14,000 humanitarian visas each year.

The government hopes to increase the annual refugee intake to around 27,000 people. However, asylum seekers who arrived by boat were treated differently than those who applied and were supported under different international programs. Those who arrived by boat were detained in Australian-funded offshore camps in the South Pacific with no prospect of resettlement in Australia. The policy was condemned as inhumane by rights groups, but the government said it had prevented them from risking their lives at sea.

A detention center in Papua New Guinea has closed, and around 100 migrants remain on the island of Nauru.