Senator Wong said the legal case and imprisonment of the WikiLeaks co-founder has been going on for too long.

Mr Assange has been imprisoned in the UK for more than four years and faces extradition to the US on espionage charges.

Appeals to stop his extradition are currently before the UK courts.

Speaking at the National Press Club, Senator Wong said the government would continue to press for Mr Assange's release.

"There are obviously limits to what you can do in terms of another country's legal proceedings and we are not a part of those proceedings," she said.

"We cannot intervene in those proceedings just as the UK and US cannot intervene in our legal proceedings."

Australian high commissioner to the UK Stephen Smith visited Mr Assange in Belmarsh Prison earlier in April, the first time an Australian official had visited him in the facility since his arrest.

The foreign minister said it would be good to continue consular assistance to the Australian while he remained in prison.

"Some of Mr Assange's advocates have been raising, rightly, whether or not the conditions in Belmarsh are appropriate," Senator Wong said.

"That is something I will be asking my high commissioner to engage about."

Last week, almost 50 Australian MPs and senators signed a letter to US Attorney-General Merrick Garland urging him to end the pursuit of the WikiLeaks co-founder.

Advocates have urged for Prime Minister Anthony Albanese to raise the issue of Mr Assange during upcoming meetings with US President Joe Biden and UK Prime Minister Rishi Sunak.

Australian Associated Press