John Howard has piled pressure on the federal government to grant protection visas for Afghan subcontractors who fear for their lives.

Foreign Minister Marise Payne is being urged to fast-track applications from interpreters, contractors and security guards as Australia’s longest war draws to a close.

Howard, who was prime minister when Australian troops were first deployed to the war-torn country in 2001, said the nation has an ethical duty to provide safe haven for Afghans who aided their cause.

“It was a moral obligation that we shamefully disregarded many years ago when we pulled out of Vietnam,” the 81-year-old told SBS TV.

“I do not want to see a repetition of that failure in relation to Afghanistan.”

People employed as subcontractors have reportedly been denied access to visas for locally engaged workers.

Howard, who has no regrets over his decision to follow the US to war in Afghanistan, said the technicality should not be used to keep those potentially in peril from the sanctuary of Australia.

“I don’t think it’s something that should turn on some narrow legalism,” the nation’s second longest-serving prime minister said.

“If a group of people gave help to Australians such that their lives and that of those immediately around them are in danger we have a moral obligation to help them.”

Taliban fighters have been advancing across the country in recent weeks as Australia and the United States end two decades of involvement in Afghanistan.

Australia has granted more than 230 visas to Afghans including family members of local workers since April 15.

-with AAP