WikiLeaks founder Julian Assange has announced the whistleblowing website is suspending publication of classified documents due to a funding crisis.

Mr Assange fronted the media at London's Frontline media club to announce that the website would be forced to fold after Christmas unless it raised about $3.3 million in funds.

He said that an "arbitrary and unlawful financial blockade has been imposed by Bank of America, Visa, MasterCard, PayPal and Western Union".

"The attack has destroyed 95 per cent of our revenue," he said.

And he warned that WikiLeaks would take legal action against companies blocking funding in Australia, the US, Britain and several European countries.

"We are throwing all our own resources into this stand against the blockade because it will mean the elimination of WikiLeaks and potentially the elimination of any other group that gets on the wrong side of these unaccountable US finance companies," he said.

"If we do not get the funds flowing again that is the end of WikiLeaks - that is the end."

US-based finance companies like Visa and Mastercard stopped processing donations for WikiLeaks in December last year after the US criticised the whistleblowing website's release of tens of thousands of sensitive diplomatic cables.

Mr Assange says WikiLeaks has been forced to run on cash reserves for the last 11 months.

"If WikiLeaks does not find a way to remove this blockade, given our current levels of expenditure we will simply not be able to continue by the turn of the new year," he said.

But Mr Assange denied his reputation had been tarnished following WikiLeaks' controversial release of US diplomatic cables and sexual assault allegations against him from two women in Sweden.

"This is absolutely not a general perception. Across the general population of the world I have more than 84 per cent name recognition," he said.

"Within Australia, personally, the approval rating for Julian Assange is double the approval rating for Julia Gillard."

Assange is appealing against a decision that he be sent to Sweden from the UK to answer questions about the sex allegations.

But despite his legal problems he said he was coping well.

"Well it's quite easy. The work is very satisfying, very demanding and one simply throws oneself into the mission," he said.

He said WikiLeaks and other whistleblower sites were no longer safe from infiltration and said WikiLeaks would unveil a new system late in November.