Edward Snowden plans to meet with international human rights groups at Moscow’s main airport, reports the New York Times, citing airport officials.

The former NSA contractor who blew the whistle on the PRISM government surveillance program, has spent almost three weeks in the airport’s transit zone because he lacks a valid U.S. passport or other valid travel documents and has not found a satisfactory asylum option.

Amnesty International and Human Rights Watch are among the groups who received an invitation emailed from Snowden to attend the meeting. Journalists and Russian government officials were excluded from the meeting, with the exception of Russian human rights commissioner Vladimir Lukin.

Some human rights advocates expressed doubts about the email’s authenticity.

The Snowden email said that he’d appreciated the offers of asylum from countries throughout the world, though many countries have declined his requests. The email also discussed the U.S. government’s “unlawful campaign” blocking his attempts to reach asylum.

“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 effect a search for a political refugee,” read the email, referring to a July 2 incident where Bolivian President Evo Morales’ plane was searched on suspicion that Snowden was on it.