The 43-year-old Australian said his decision to leave was not for reasons “reported by the Murdoch press” but did not elaborate.
Sky News, part-owned by Rupert Murdoch, had reported earlied on Monday that Mr Assange was considering leaving the embassy due to failing health. He added that his health had been affected by his two-year confinement without direct sunlight or being outside, but did not elaborate.
Mr Assange has been living in the embassy as part of a bid to avoid extradition to Sweden, where there is a warrant against him over alleged sexual offences against two women.
In a joint press conference, which began around 20 minutes after it was due to start at 9am, the Ecuadorian Foreign Minister Ricarod Patino said that Ecuador was trying to start a dialogue with the UK foreign office about Assange’s situation.
Mr Patino said there had been “two lost years” for everyone involved, including the two Swedish women at the centre of the saga. “There has not been justice for anyone. The situation must come to an end,” he said.
He referred to recent changes to the extradition laws in the UK which he believed would mean Mr Assange would not be facing extradition if the case started today.
“Over the coming weeks I will be trying out set up a meeting with the UK foreign secretary,” he said. “We believe that the recent reforms create a better climate for us to try to reach an agreement.”
As journalists continued to gather near the embassy, WikiLeaks spokesman Kristinn Hrafnsson shed some light on exactly what Mr Assange’s “soon” may mean.
“The world is not coming to an end,” he told reporters. “The plan, as always, is to leave as soon as the UK Government decides to honour its obligations in relation to international agreements.”
Police officers continued to wait outside the embassy, as they have done for two years in a 24-hour operation that Mr Assange said has cost £7m.
“There has been very significant misreporting on this case” says #Assange#c4news