Russian Prime Minister Putin railed against the detention of the 39-year-old Mr Assange, the Australian founder of the website which has been releasing thousands of secret US diplomatic cables as well as Pentagon communiques.
"Why was Mr Assange hidden in jail? Is that democracy? As we say in the village: the pot is calling the kettle black," Mr Putin said.
"I want to send the ball back to our American colleagues."
Despite his defence of Mr Assange, Mr Putin was portrayed in an embarrassing light by some of the leaked cables. In one, US Secretary of State Hillary Clinton called him a "behind the scenes puppeteer" dissatisfied with his role.
Others detailed allegations of high-level Russian corruption and referred to Mr Putin as an "alpha dog".