Ecuador's government has acknowledged that it had partly restricted internet access for Julian Assange, the founder of anti-secrecy group WikiLeaks, who has lived in the country's London embassy since mid-2012.

WikiLeaks said Mr Assange lost connectivity on Sunday, sparking speculation Ecuador might have been pressured by the United States due to the group's publication of hacked material linked to US Democratic presidential candidate Hillary Clinton.

In a statement, Ecuador's leftist government said WikiLeaks' decision to publish documents impacting the US election campaign was entirely its own responsibility, and the South American country did not cede to pressure from other nations.

"In that respect, Ecuador, exercising its sovereign right, has temporarily restricted access to part of its communications systems in its UK Embassy," it added in a statement.

"The Ecuador government respects the principle of non-intervention in other countries' affairs, it does not meddle in election processes under way, nor does it support any candidate specially."

Earlier yesterday, the US State Department said it had no role in restricting Mr Assange's internet access.

"While our concerns about WikiLeaks are longstanding, any suggestion that Secretary [John] Kerry or the State Department were involved in shutting down WikiLeaks is false," State Department spokesman John Kirby said in a statement.

Mr Assange was granted asylum by Ecuador after a British court ordered him extradited to Sweden to face questioning in a sexual molestation case involving two female supporters.

WikiLeaks said it activated "contingency plans" after Mr Assange's cut-off, and Ecuador said that its action did not stop the group continuing "journalistic activities".

Ecuadorean President Rafael Correa has long backed Mr Assange's right to free speech and has also supported Ms Clinton publicly.

"For the good of the United States and the world ... I would like Hillary to win," he told broadcaster Russia Today last month.