Julian Assange's lawyer has urged Prime Minister Scott Morrison to raise her client's extradition case when he meets with US vice president Mike Pompeo at the weekend.

Jennifer Robinson was in Canberra to drum up support for the WikiLeaks founder who is fighting extradition to the US where he faces numerous charges including espionage.

His case should be of "great concern" to all Australians, Ms Robinson - who represents Assange in the UK - told reporters on Wednesday.

"This is a dangerous precedent for all of the media and a dangerous precedent being set against an Australian citizen."

She called on Mr Morrison and Foreign Minister Marise Payne to raise the issue when they host Mr Pompeo at AUSMIN in Sydney on Sunday.

Assange, 48, is serving a 50-week prison sentence in the UK for skipping bail after he spent seven years holed up in the Ecuadorian embassy in London.

He fled to the embassy in 2012 to avoid being extradited to Sweden for questioning over sexual assault allegations.

Ms Robinson, who last saw Assange in Belmarsh prison a few weeks ago, has "serious concerns" for his health.

"His health has obviously deteriorated significantly and (there's) likely permanent damage on his health as a result from his time in the embassy," she said.

"He does not deserve the treatment he has received and it's time for the Australian government to speak up."

The US has indicted Assange on 18 charges including allegations of conspiring with intelligence analyst Chelsea Manning to hack into a classified Pentagon computer.

His extradition case is due to begin in February.

But former Greens senator Scott Ludlam, who has known Assange since 2011, said the government should not wait for the matter to grind through British courts for "two or three years".

"Julian Assange needs to come home," he told reporters.