The State Department said the United States has no involvement in legal proceedings in London following the arrest of WikiLeaks founder Julian Assange.

Assange appeared on December 7 afternoon at a court in London after turning himself in to Scotland Yard earlier in the day.

A British judge denied Assange bail after the WikiLeaks founder told the court he would fight efforts to extradite him to Sweden to face a sex-crimes investigation.

At the State Department, Spokesman Philip Crowley called the case "an issue between Britain and Sweden," and said that the US continues its own investigation.

Crowley would not answer questions about whether the U.S. would seek to extradite Assange to the United States, saying only that the US investigation is ongoing.

"What we're investigating is a crime under U.S. law. The provision of 250-thousand classified documents from someone inside the government to someone outside the government is a crime," Crowley said, AFP reported.

Assange appeared at before City of Westminster Magistrates' Court in London after turning himself in to Scotland Yard earlier on Tuesday, capping months of speculation over an investigation into alleged sex crimes committed in Sweden over the summer.

Assange and his lawyers claim that the accusations stem from a "dispute over consensual but unprotected sex" in Sweden in August, and have claimed the case has taken on political overtones.