WikiLeaks founder Julian Assange says the group will publish about one million documents related to the US election and three governments in coming weeks, but denied the release was aimed at damaging Hillary Clinton.
Mr Assange, speaking via a video link on Tuesday, said the documents would be released before the end of the year, starting with an initial batch in the coming week.
Mr Assange, 45, who remains at the Ecuadoran embassy in London where he sought refuge in 2012 to avoid possible extradition to Sweden, said the election material was "significant" and would come out before the November 8 US presidential election.
He criticised Ms Clinton, the Democratic presidential candidate, for demonising his WikiLeaks group's work after a spate of releases related to the Democratic National Committee before the Democratic political convention this summer.
Mr Assange said her campaign had falsely suggested that accessing WikiLeaks data would expose users to malicious software.
But he denied the release of documents relating to the US election was specifically aimed at damaging Ms Clinton, saying he had been misquoted.
"The material that WikiLeaks is going to publish before the end of the year is of ... a very significant moment in different directions, affecting three powerful organisations in three different states as well as ... the US election process," he said via a video link at an event marking the group's 10th anniversary.
He said the material would focus on war, weapons, oil, mass surveillance, the technology giant Google and the US election, but declined to give any details.
"There has been a misquoting of me and Wikileaks publications ... (suggesting) we intend to harm Hillary Clinton or I intend to harm Hillary Clinton or that I don't like Hillary Clinton. All those are false," he said.
Mr Assange had told Fox News in an interview conducted by satellite in August that the group would release significant information related to Ms Clinton's campaign.
Mr Assange also signalled changes in the way WikiLeaks is organised and funded, saying the group would soon open itself to membership.
He said the group was looking to expand its media ties beyond the 100 outlets it already works with.
He told journalists gathered at a Berlin theatre that the group's work would continue, even if he had to resign in the future, and he appealed to supporters to fund its work. He also held up copies of several forthcoming books.
Mr Assange and his lawyer said Britain's vote to leave the European Union could complicate his situation by limiting his ability to appeal to the European Court of Justice or the Council of Europe, a European human rights body.
Asked how he felt after four years in the embassy, he said "pale" and joked he would be a good candidate for medical study since he was otherwise healthy but had not seen the sun in over four years.
Mr Assange is wanted in Sweden for questioning about allegations that he committed rape in 2010. He denies the charges, and says he fears subsequent extradition to the United States, where a criminal investigation into the activities of WikiLeaks is underway.