'The alliance is very strong': PM to consult with US over Afghan mission

Prime Minister Malcolm Turnbull has restated Australia's intimate alliance with the US, pre-empting close consultations over our role in Afghanistan.

Australian Prime Minister Malcolm Turnbull walks with US President Donald Trump to the family photo during the G20 Summit in Hamburg Source: AAP

Malcolm Turnbull insists Australia and the US are the staunchest of allies as both countries look to consult on the future of the Afghanistan mission.

The prime minister wasn't keen to speculate on any increased involvement on the part of Australia, after Donald Trump outlined his new plan to fight the Taliban.

"We already are one of the most substantial contributors to the coalition effort in Afghanistan," he told reporters during a visit to Tumut in southern NSW on Wednesday.

"Any further requests the Americans have we will obviously look at that and consult with them."

Mr Turnbull said he wasn't ruling out further involvement, warning there is a long game.

"I think the Western coalition commitment to Afghanistan you should expect it will be very long-term as it has been," he said.

The prime minister described the US alliance as very intimate, pre-empting close consultations.

"We are very, very staunch allies in the global war to defeat terrorism.

"The alliance is very, very strong - none stronger."

Earlier, Defence Industry Minister Christopher Pyne said the policy change outlined by the US president on Tuesday signals a determination on the part of the administration to defeat the strengthened Taliban.

"Setting deadlines and troop withdrawals means that the Taliban have been able to, as (Mr Trump) points out, wait out the United States," he told ABC radio.

The minister expects Australia will be asked to contribute, but he was not pre-empting any decision.

"We won't make any hasty decisions about increasing Australia's engagement in Afghanistan."

Mr Pyne cautioned that Australians have died in Afghanistan previously and any request to change the nation's role in the conflict would be a serious one.

Australia already increased its mission by 30 earlier this year, bringing the total troops in Afghanistan to 300.

Reports suggest America will boost its 8400 forces in Afghanistan by 4000, but Mr Trump did not confirm this when announcing the new plan.