The Australian appeared downcast and mumbled during a case management hearing in the Westminster Magistrates Court, ahead of his extradition trial in February.

Clean-shaven and wearing a white shirt with a blue sweater and navy coat, the 48-year-old WikiLeaks founder made a fist to supporters in the public gallery, who included Australian journalist John Pilger and former London mayor Ken Livingston.

However he seemed to struggle to remember his birth date when asked to give it at the beginning of Monday's hearing.

Assange's barrister Mark Summers QC applied to have the extradition trial delayed for three months and also requested the hearing be extended for longer than the set five days, saying new evidence had come to light.

However District Judge Vanessa Baraitser refused his request before asking Assange whether he understood what had occurred.

"Not really. I can't think properly," Assange mumbled, before adding that the US government had an unfair advantage in the case.

"I don't understand how this is equitable. This superpower had 10 years to prepare for this case and I can't access my writings. It's very difficult where I am to do anything but these people have unlimited resources.

"They are saying journalists and whistleblowers are enemies of the people. They have unfair advantages dealing with documents. They (know) the interior of my life with my psychologist. They steal my children's DNA. This is not equitable what is happening here."

Earlier, Summers had argued that new evidence in the case only came to light since Assange's arrest six months ago.

Summers referred to allegations that Spanish contractors spied on Assange on behalf of the US government while he held asylum-seeker status inside the Ecuadorian embassy.

Earlier this month Spain's National Court announced it was investigating whether a Spanish security firm spied on Assange in the embassy with hidden microphones and other devices and passed information to Ecuadorean and US authorities.

"That's merely one tentacle of the octopus, but we hope the court can see the magnitude of the evidential task," Summers told the court.

"To be blunt, we need more time."

Summers also expressed concern about the conditions under which Assange was being held, including the fact he has no access to a computer.

"It was only last week that we were able to pass him documents," the barrister said.

James Lewis, for the US government, said his side was strongly against any further delay in the case.

"The defence have had five-and-a-half months to prepare that evidence and we would resist a further extension," he argued.

Lewis said there was no question over the legality of Assange's actions, and accused the Australian of knowingly risking the torture, death or arbitrary detention of US informants.

"It is not journalistic, actually it is criminal, both in the United States and the United Kingdom," he said.

The US government wants to try Assange over the release of thousands of confidential and classified Pentagon files about the wars in Iraq and Afghanistan, including the names of local informants in those countries.

Assange and his supporters say he was acting as a journalist and the information he released revealed multiple war crimes committed by coalition forces in those countries.

He faces 17 charges of spying and one of computer hacking, with a maximum sentence of 175 years if found guilty in the US.

Judge Baraitser refused to give the defence more time or extend the trial length and adjourned the case until November 18, with the full trial still set for February.

Australian Associated Press