The letter was written jointly Tuesday by Lonnie Snowden and his lawyer, Bruce Fein.
He describes his son as a modern-day Paul Revere, which is a 180-degree turn from his initial requests for his son to stop the leaks and come home.
The letter comes as it appears that Snowden is running out of options for asylum. Out of all the countries on Snowden's list for seeking political asylum - so far, there are no takers.
Tuesday morning, India denied Snowden's asylum request. The Indian embassy in Moscow had received a request for asylum from Snowden, External Affairs Ministry spokesman Syed Akbaruddin told reporters.
He said India carefully examined the request and decided to turn it down. The government has "concluded that we see no reason to accede to that request," Akbaruddin said.
This comes after Snowden reportedly dropped his bid for asylum in Russia. The anti-secrecy group WikiLeaks has said that Snowden has applied to more than 20 countries for asylum. Several of those countries said he cannot apply from abroad. Officials in Germany, Norway, Austria, Poland, Finland, Switzerland and Spain all said he must make his request on their soil.
WikiLeaks said requests have also been made to Bolivia, Brazil, China, Cuba, Ecuador, France, Iceland, India, Italy, Ireland, Netherlands, Nicaragua, Spain and Venezuela.
The group also posted a statement attributed to Snowden on its website late Monday, in which he slams President Barack Obama for "using citizenship as a weapon."
"Although I am convicted of nothing, (the United States) has unilaterally revoked my passport, leaving me a stateless person," Snowden says in the statement. "Without any judicial order, the administration now seeks to stop me exercising a basic right. A right that belongs to everybody. The right to seek asylum...Their purpose is to frighten, not me, but those who would come after me."
Russian news agencies are quoting the Kremlin as saying Snowden withdrew his request when he learned about the terms Moscow set out.
Russian President Vladimir Putin said Monday that Russia was ready to shelter Snowden, but he must stop leaking U.S. secrets. At the same time, Putin said he had no plans to turn over Snowden to the United States.
But Russia's unwillingness to extradite Snowden is seen by some as a slap in the face to the U.S.
Snowden has been on the run since he exposed highly secret National Security Agency surveillance programs. He is believed to be staying in the transit area of Moscow's airport since arriving there from Hong Kong on June 23.
A senior U.S. official told ABC News last week they expected Snowden to run out of options about this time, so it would appear things are starting to play into the U.S' hands now. However, Snowden claims he still has more secrets to release.
In an interview on Russian television, the Bolivian president said he would be willing to consider granting asylum to Snowden. However, as soon as Snowden crosses the Atlantic or Pacific oceans, he would run into a U.S. extradition treaty.
The Associated Press and ABC News contributed to this report.