Swedish officials say they issued the international alert because the 39-year-old Australian has not made himself available for a meeting with prosecutors. Assange's lawyer, Mark Stephens, said that Swedish officials have turned down repeated offers to speak to Assange.
Assange's secret-spilling group has leaked a series of confidential U.S. intelligence and diplomatic reports this year, including the disclosure earlier this week of hundreds of classified State Department cables. U.S. officials have reacted with outrage, with Secretary of State Hillary Rodham Clinton accusing WikiLeaks of acting illegally and promising "aggressive steps to hold responsible those who stole this information."
Clinton said she discussed the leak with her colleagues at a security summit in Kazakhstan and the revelations. The leaks include unflattering descriptions of some foreign leaders and requests for U.S. diplomats to gather personal information on others. They have revealed Western concerns that Islamist militants might get access to Pakistan's nuclear material and American skepticism that Islamabad will sever ties to Taliban factions fighting in Afghanistan. They also showed U.S. doubts over the abilities of Pakistan's weak, unpopular civilian government
"I have certainly raised the issue of the leaks in order to assure our colleagues that it will not in any way interfere with American diplomacy or our commitment to continuing important work that is ongoing," Clinton said. "I have not any had any concerns expressed about whether any nation will not continue to work with and discuss matters of importance to us both going forward."
Several officials at the summit echoed her comments.
Assange is wanted on suspicion of rape, sexual molestation and unlawful coercion. The exact nature of the allegations aren't completely clear because formal charges have not been filed.
The former computer hacker's exact whereabouts remain unknown, although he has conducted online interviews with some media organizations.
Assange told Time magazine that Clinton should resign "if it can be shown that she was responsible for ordering U.S. diplomatic figures to engage in espionage in the United Nations" in violation of international agreements.
The White House said his statementsand U.S. diplomats do not engage in spying.
Assange's lawyer, Stephens, who also represents The Associated Press, said his London law firm was investigating whether the Swedish case was linked to U.S. promises to prosecute those behind the leaks.
Stephens complained that Assange has yet to receive formal notice of the allegations he faces - which he described as a legal requirement under European law.
The lawyer was scathing in his condemnation of Sweden's Director of Public Prosecution Marianne Ny, saying he'd never come across a prosecutor who has "such casual disregard" for her obligations.
"Given that Sweden is a civilized country, I am reluctantly forced to conclude that this is a persecution and not a prosecution," Stephens wrote in an e-mail.
Stephens has previously said that the allegations were made after Assange had consensual sex with two women who turned on him after becoming aware of each other's relationships. Swedish prosecutors have disagreed about whether to label the most serious charge as rape.
Sweden's Supreme Court was reviewing Assange's appeal of the order to detain him. Court official Kerstin Norman, who is handling the case, said a decision is expected late Wednesday or Thursday.
Prosecutor Marianne Ny said that a European arrest warrant had been issued for Assange, but said that "for secrecy reasons, she cannot give more information concerning this matter at the moment."