WikiLeaks founder Julian Assange stands by his offer to go to the United States now that Chelsea Manning is being released, he told a press conference.

Speaking from the Ecuadorian embassy in London via social media, he signalled there would be "many discussions" on his future before Manning leaves prison in May.

He welcomed Barack Obama's decision to free the former soldier jailed for handing over classified documents to the anti-secrecy organisation.

The outgoing US president used his final hours in the White House to allow Manning to go free nearly 30 years early.

The transgender former intelligence analyst, born Bradley Manning, said she had passed on government and military documents to raise awareness about the impact of war.

Mr Assange, who has been living at the Ecuadorian embassy since the summer of 2012 for fear of being extradited to the US, praised campaigners for their role in the decision.

He was interviewed in the embassy in November in the presence of prosecutors from Sweden, where he faces a sex allegation.

He denies the claims, but insists he faces extradition to the United States for questioning over the activities of WikiLeaks if he leaves the embassy.

WikiLeaks tweeted last week: "If Obama grants Manning clemency Assange will agree to US extradition despite clear unconstitutionality of DoJ (Department of Justice) case."

Asked whether he will now leave the embassy, he said: "I stand by everything I said, including the offer to go to the United States if Chelsea Manning's sentence was commuted. It is not going to be commuted until May - we can have many discussions to that point.

"I have always been willing to go to the United States provided my rights are respected."

Mr Assange said there has been a seven-year long attempt to build a prosecution against him and WikiLeaks in the US, and his name is on several warrants and subpoenas.

"As of this year it is active and ongoing," he said.

Mr Assange said if it took him going to the US to "flush out" the case being prepared against him, or to drop it, then "we are looking at that".

He said the UK's Crown Prosecution Service had refused to confirm or deny whether there was an extradition request from the US.

Mr Assange said he loved what WikiLeaks was doing, adding it had published more than 10 million documents that had never been made public before, which had contributed to justice and led to innocent people being released from prison.

Asked if he would receive different treatment under President Donald Trump, Mr Assange replied: "It remains to be seen."

Questioned why he had not gone to Sweden to be interviewed, he pointed out he had never been charged "at any stage", had already been cleared by the Swedish authorities in relation to the allegation, while the United Nations had "firmly found" that he was being detained illegally.

He added that Sweden was refusing to guarantee that he would not be extradited to the US.