Heartbreaking losses in the past two days will not break the resolve of Australia to complete its Afghan Mission, Prime Minister Julia Gillard said on Thursday following the deaths of five diggers on Wednesday, three of them killed by 'green-on-blue' assault.

Cutting short her Pacific Islands tour when the news broke about the fresh Australian casualties in the decade-old Afghan War, Ms Gillard said she was saddened by the fact that she had attended so many funerals for fallen Diggers, 19 at the last count, according to reports by News Ltd.

What just happened was a "physical blow," the prime minister said.

"This is our single worst day in Afghanistan. Indeed, I believe this is the most losses in combat since the days of the Vietnam War and the battle of Long Tan," The Herald Sun quoted Ms Gillard as saying on Thursday.

With Australia's death toll now at 38, Ms Gillard said it is almost natural that many would question the merits and wisdom of the Afghan Mission, especially in light of the rising incidence of 'insider attacks' that already claimed the lives of many NATO-aligned troops.

Australia already lost seven soldiers in such assaults since last year.

However, Ms Gillard stressed that amidst the spiking numbers of deaths and injuries inflicted on members of the Australian Defence Force (ADF) serving in Afghanistan, stronger resolve must be displayed by all Australian.

There will be no hasty withdrawal of troops from the war-torn nation, Ms Gillard asserted.

Defence Minister Stephen Smith said on Friday the ADF will stay the course despite the killings of three Diggers mentoring members of the Afghan Army and the death of two Aussie Special Forces in a chopper crash, which all occurred within a 24-hour timeframe.

"It doesn't do anything to my resolve to stay the course because staying the course is absolutely the right thing to do," Mr Smith was reported by ABC as saying on Friday during a news briefing on the twin incidents.

"We can't stay in Afghanistan forever, we don't want to stay in Afghanistan forever, and equally it would be wrong to leave prematurely or to leave tomorrow as some people suggest," he added.

Mr Smith also disclosed the name of the assailant responsible for the latest Australian deaths.

The killer was identified as 'Hikmatullah', who shot the Diggers while they were resting and climbed over the fence to escape on foot.

He served as a guard for Australia's main base prior to the shooting and according to Mr Smith, a team composed of coalition and Afghan soldiers has been dispatch to hunt him down.

For his part, Opposition Leader Tony Abbott is supportive of the government's position to honour its Afghan commitment notwithstanding the hostile behaviour of rogue elements of the local security forces.

In an interview with Nine Network Friday morning, Mr Abbott said: "I don't think Australians want us to be a country ... that cuts and runs."

Staying there till the end of 2014 should mean that Aussies will contribute to the uplift of Afghan lives, especially of young girls who were forbidden by the Talibans to attend schooling.

"It's got to be to our credit as a nation that we are prepared to offer our help to this nation," Mr Abbott said.

Yet for independent MP Andrew Wilkie, himself a former military and intelligence officer, the Afghan Mission does not serve Australia's national interest.

"Being in Afghanistan now is not in Australia's national interest and was avoidable," Mr Wilkie was reported by the Australian Associated Press (AAP) as saying on Friday.

He blamed the past Liberal government of John Howard and that of Kevin Rudd's and Ms Gillard's for their unwillingness to bring home the Australian troops when they had valid reasons to do so.

"The five soldiers who died in Afghanistan this week died unnecessarily and Howard, Rudd and Gillard all have blood on their hands," Mr Wilkie said.