U.S. officials have contacted authorities in Hong Kong to request the extradition of Edward Snowden, the former Booz Allen employee charged with espionage and theft of government property.
"Hong Kong has been a historically good partner of the United States in law enforcement matters, and we expect them to comply with the treaty in this case," Donilon said.
Snowden faces up to 30 years in prison on three espionage charges, but the legal battle to extradite him could take months or even years.
Snowden can try to avoid extradition by claiming he is being sought for political reasons and can ask for asylum.
He was charged earlier this month for leaking classified information to The Guardian and The Washington Post revealing National Security Agency surveillance of millions of domestic phone calls and major websites such as YouTube and Facebook.