Fugitive American Whistleblower Edward Snowden takes a swipe at American authorities for trying to deny him the “right” to take up offers of asylum from some “brave” states.

"I have been extremely fortunate to enjoy and accept many offers of support and asylum from brave countries around the world. These nations have my gratitude ...” said Snowden in a letter to a Human Rights Watch official.

"Unfortunately, in recent weeks we have witnessed an unlawful campaign by officials in the U.S. government to deny my right to seek and enjoy this asylum under Article 14 of the Universal Declaration of Human Rights.”

The American whistleblower, who has invited human rights groups to meet him on Friday at a Moscow airport where he is locked since leaving Hong Kong on June 23, also blasted some other countries for cooperating with the United States for his arrest.

"The scale of threatening behavior is without precedent: never before in history have states conspired to force to the ground a sovereign President's plane to affect a search for a political refugee."

He was referring to last week's incident in which some European countries including France, Italy and Spain denied their airspace to the airplane carrying Bolivian President Evo Morales because U.S. officials suspected that Snowden was on board the plane . The plane was later forced to land in Vienna and according to Austrian officials was fully searched before being allowed to head for Bolivia.

Snowden who is accused of espionage charges by the U.S. said that such a trend “represents a threat not just to the dignity of Latin America or my own personal security, but to the basic right shared by every living person to live free from persecution."

Snowden is to meet with representative of human rights groups at 17:00 Moscow time (1300 GMT) to discuss the "next steps forward in my situation".