The number of asylum seekers resettled in Australia would rise dramatically under a new Greens proposal.

Under the plan, to be launched on Saturday, 40,000 asylum seekers would be resettled on humanitarian grounds every year - an increase by about 26,000 taken in by Australia in 2014-15.

A further 10,000 would be taken in as part of a skills program, while offshore detention facilities on Manus Island and Nauru would be shut.

'Australia doesn't need to respond to people seeking our protection by turning our backs or locking them up,' Greens leader Richard Di Natale said in a statement.

Greens immigration spokesperson Sarah Hanson-Young said closing offshore detention facilities enabled the program to be 'cost-neutral'.

'Closing down Manus and Nauru would save almost $3 billion dollars,' she told Sky News on Saturday.

'That is an awful lot of money to keep 2000 people - men, women and children - detained on those island camps.'

'Our nation has been built of the back of migrants coming here for a better life, we've had such a positive history in this,' she said.

'Sadly the last few years that has gone to the wayside and we've been tarnished with the children in detention and the issues of scandals inside our detention centres and this kind of cruel policy.

Senator Hanson-Young said the proposed plan is different because it does not simply involve closing offshore camps, but puts in place a 'proactive strategy' to help people arrive in Australia safely.

'Our current policy uses the abuse of children in detention centres as a deterrent,' she said.

Labor has expressed concern with the policy, saying it could lead to an opening of seaways.

Federal Opposition Leader Bill Shorten said a clear message had to be sent to people smugglers against sending people to Australia by boat.

'There is no compassion in rewarding people smugglers and their business model to entice vulnerable people onto unsafe boats, then they drown at sea,' he said.

With AAP