WASHINGTON - Barack Obama has made his strongest condemnation yet of WikiLeaks, as supporters of Julian Assange demonstrated for his release.
In a call to the Turkish Prime Minister, Recep Tayyip Erdogan, the US President ''expressed his regrets for the deplorable action by WikiLeaks'', the White House said.
The comments, and similar statements in a call to his Mexican counterpart, Felipe Calderon, were Mr Obama's most forceful yet against the website, whose disclosure of a trove of secret US diplomatic cables has won it international condemnation and praise.
Mr Obama's call to Mr Erdogan could be seen as an effort to smooth ruffled feathers in Turkey - a key regional US ally - where officials including the Prime Minister have railed against some of the information divulged by the documents.
Demonstrations took place across Spain on Saturday - including one by hundreds of people outside the British embassy in Madrid - calling for the release from a London jail of Mr Assange, the website's Australian founder, who is awaiting possible extradition to Sweden to face sexual assault allegations.
There were also demonstrations in London and Amsterdam.
The Spanish website Free WikiLeaks called for demonstrations in Buenos Aires, Mexico City, Sao Paulo, Bogota and Lima. In a manifesto entitled ''For freedom, say no to state terrorism'', it demanded Mr Assange's release and ''restoration of the WikiLeaks domain''.
''Given that no one has proved that Assange is guilty of the offences he is accused of and that WikiLeaks is not implicated in any of those'', the website also urged that the credit card giants Visa and MasterCard rescind their decisions to cut off payments from the website's supporters.
Mr Assange is due to appear in a London court for a second time tomorrow after being arrested on a warrant issued by Sweden. Prosecutors there want to question him about two women's allegations of rape and sexual molestation.
WikiLeaks insists the allegations are a politically motivated attempt to smear Mr Assange.
Mr Assange, 39, has been transferred from the main section of Wandsworth prison to an isolation unit, said Jennifer Robinson, one of his legal team.
His lawyers have complained that he is getting no recreation time in prison, is having difficulties making phone calls out, and has not been allowed to have a laptop in his cell.
''He is on his own,'' Ms Robinson said.
Mr Assange was described as in ''very good'' spirits but ''frustrated'' that he could not answer the allegations that WikiLeaks was behind cyber attacks against the credit card firms that have refused to do business with the website.
''He told me he is absolutely not involved and this is a deliberate attempt to conflate WikiLeaks, which is a publishing organisation, with hacking organisations, which are not,'' Ms Robinson said.
Mr Assange's mother, Christine, was quoted as saying she was worried for her son because ''massive forces'' were ranged against him.