Senate Intelligence Committee Chairwoman Dianne Feinstein says she is surprised China didn't use Edward Snowden's extradition as a chance to improve relations with the United States.

If follows a US request to extradite the US intelligence fugitive from Hong Kong.

Mr Snowden, an intelligence contractor, fled to the country in May after revealing extensive internet and phone surveillance by US intelligence.

He travelled to Moscow on Sunday but is thought to be in transit before leaving for Venezuela or Ecuador, via Cuba.

Speaking on CBS's Face the Nation Ms Feinstein said: "China clearly had a role in this."