The Guardian:

Henry Kissinger was US secretary of state and national security adviser during the period covered by the collection, and many of the reports were written by him or were sent to him. Thousands of the documents are marked NODIS (no distribution) or Eyes Only, as well as cables originally classed as secret or confidential.

Assange said WikiLeaks had undertaken a detailed analysis of the communications, adding that the information eclipsed Cablegate, a set of more than 250,000 US diplomatic cables published by WikiLeaks from November 2010 and over the following year. He said WikiLeaks had developed sophisticated technical systems to deal with complex and voluminous data.

Top secret documents were not available, while some others were lost or irreversibly corrupted for periods including December 1975 and March and June 1976, said Assange.

Assange added that his mother, who lives in Australia, had told him he was being kept at the embassy "with nothing to do but work on WikiLeaks material". Indeed.

In opening the press conference, Assange began with a quote from George Orwell's "1984": “He who controls the past controls the future. He who controls the present controls the past.”