Julian Assange's appeal against a detention order issued by Swedish police has been rejected by the country's Supreme Court.
The Wikileaks founder has been living at Ecuador's London embassy since June 2012 to avoid extradition to Sweden, where he is wanted for questioning over allegations of sexual assault.
Assange denies the allegations against him.
WikLeaks founder Julian Assange announced he will be leaving the Ecuadorian embassy "soon" after two years at the building.
Assange told a press conference, "I am leaving the embassy soon - but perhaps not for the reasons that the Murdoch press and Sky News are saying at the moment".
By Juliet Bremner: UK Editor
There is a huge number of media outside, but a police officer has just been out to relay a message that there will be no further events or movement here at the Ecuadorian embassy today.
I suspect this is a big publicity stunt to try and get the British Government to engage in a discussion about his release.
Julian Assange has hinted at unspecified health "difficulties" - mentioning in particular the lack of outdoor space and sunlight at the Ecuadorean Embassy in London where he has been holed up for two years.
In relation to my health, as you can imagine ... being detained in this country in various ways for four years, and then in this embassy for two years ... It is an environment in which any healthy person would find themselves soon enough with various difficulties.
Julian Assange has stressed he has not been charged with an offence in the UK or in Sweden "at any time".
"The basis under which my asylum was granted here [at the Ecuadorian embassy] is the ongoing US investigation into me and WikiLeaks", he said during a press conference.
"I am leaving the embassy soon, but perhaps not for the reasons that the ... press are saying at the moment," Julian Assange has told reporters.
Julian Assange says: "It is often falsely reported that women in Sweden have accused me of the serious crime of rape. That is false. No woman has done so."
WikiLeaks founder Julian Assange has said the position Ecuador has taken on his case "is the correct one".
Assange sought refuge inside Ecuador's London embassy two years ago in a bid to avoid extradition to Sweden for questioning over sexual misconduct allegations.
He has denied the claims made against him.
Ecuador's foreign minister has said it is "time to free" WikiLeaks founder Julian Assange.
Speaking at a press conference inside the Ecuadorian embassy, Ricardo Patino Aroca said, "Two years is simply too long, it is time to free Julian Assange - it is time for his human rights to be respected."
Police have erected a fence around the steps of the Ecuadorean embassy in London ahead of an expected news conference by Julian Assange.
A police officer could be heard arguing with a someone who emerged from the embassy about whether the pavement was public or private property.
"Police can deal with it, not you," the officer said. "Let me call the council then," he replied.