Lon Snowden spoke to journalists upon arrival at New York's John F. Kennedy International Airport Wednesday after a trip to Russia where he went to see his son.
He said his son knew many things that could be made public.
According to Snowden Sr., he liked his visit to Russia and planned to pay another visit to that country, although he did not yet know when.
He also said his son Edward was feeling well and comfortable in Russia.
Lon Snowden said he gave Edward his parental advice not to return to the US, but in any case, it was up to Edward to decide.
When asked about his immediate plans, Snowden Sr. said he was going to a hotel to have some rest. He left the airport in his personal car.
Edward Snowden, 30, was accused in the US of leaking information on the National Security Agency's programmes of electronic eavesdropping.
He received temporary asylum in Russia after spending more than a month in the transit zone of Moscow's Sheremetyevo airport.
US authorities claim that Snowden encroached on two clauses of the 1917 law on espionage by making public without authorisation some secret data pertaining to national defence.
In addition, he is charged with stealing property of the US government. He is facing a grim prospect of 10 years in jail on each of the three charges if he returns to American soil.