British Home Secretary, Priti Patel, signed an order to extradite WikiLeaks co-founder, Julian Assange, to the US on Friday, Anadolu News Agency reports.
Assange's extradition order was passed to the Secretary by the UK courts last month, confirming that the US assurances on how Assange would be treated were sufficient for extradition.
Assange's legal team is expected to file a cross-appeal against Patel's decision. Home Office has confirmed Assange has now 14 days to appeal.
The order said the UK courts found that the extradition would not be "incompatible with his human rights," adding that "he will be treated appropriately" in the US.
"Under the Extradition Act 2003, the Secretary of State must sign an extradition order if there are no grounds to prohibit the order being made. Extradition requests are only sent to the Home Secretary once a judge decides it can proceed after considering various aspects of the case," a Home Office spokesperson said.
"On 17 June, following consideration by both the Magistrates' Court and High Court, the extradition of Mr Julian Assange to the US was ordered. Mr Assange retains the normal 14-day right to appeal."
"This is a dark day for Press freedom and for British democracy," a statement from DontExtraditeAssange campaign group said in a statement.
"Anyone in this country who cares about freedom of expression should be deeply ashamed that the Home Secretary has approved the extradition of Julian Assange to the United States the country that plotted his assassination," the statement said.
It added that Patel "will forever be remembered as an accomplice of the United States in its agenda to turn investigative journalism into a criminal enterprise."
"Today is not the end of the fight," the statement said.
"It is only the beginning of a new legal battle. We will appeal through the legal system; the next appeal will be before the High Court," it added.
Assange will face 18 counts of hacking the US government computers and violating the espionage law if he is extradited to the US and a potential prison sentence for years.
He was dragged out of Ecuador's embassy building in London last year, where he took refuge for more than seven years.
The British police said he was arrested for skipping his bail in 2012 and on behalf of the US due to an extradition warrant.
Later, he was found guilty of breaking his bail terms in 2012 after failing to surrender to security services by the Westminster Magistrates' Court and given a 50-week prison term.