The United States on Thursday denied any involvement in the ongoing diplomatic row between Britain and Ecuador over Julian Assange, the founder of the WikiLeaks website that has released embarrassing U.S. diplomatic cables.

State Department spokeswoman Victoria Nuland called the row an issue among Britain, Ecuador and Sweden, as the Nordic nation is seeking Assange's extradition for allegations of rape and sexual assault by two Swedish women.

"It is an issue among the countries involved, and we're not planning to interject ourselves," Nuland told reporters at a regular news briefing.

She rejected the claim that Washington was pushing Britain to enter the Ecuadoran embassy in London and remove Assange, where the 41-year-old Australian has taken refuge since June 19 to avoid extradition.

"I have no interim information to indicate that there is any truth to that at all," Nuland said.

Ecuadorian Foreign Minister Ricardo Patino announced his country's decision on Thursday to grant Assange political asylum, saying Ecuador believed his fears of having an unfair trial and eventually being extradited to the United States are legitimate.

Disappointed by the Ecuadorian move, Britain threatened to storm the embassy to seize Assange and Foreign Secretary William Hague vowed not to allow him "safe passage" out of the country.

The U.S. Department of Justice launched a criminal investigation against Assange following the 2010 release of U.S. war documents relating to Iraq and Afghanistan as well as the diplomatic cables.