U.S. Army whistleblower Chelsea Manning has been denied entry to Canada.

In a letter Manning posted to Twitter, the Canadian government told her she is barred from entering the country. The letter states that Manning is “inadmissible on grounds of serious criminality for having been convicted of an offense outside Canada.”

Further down in the letter, it says that “if committed in Canada this offense would equate to an indictable offense, namely Treason described under section 46(2)(B) of the Criminal Code of Canada, punishable under section 47(2)(C) of the Criminal Code of Canada, for which a maximum penalty of 14 years imprisonment may be imposed.”

Manning was arrested in 2010, after sending hundreds of thousands of military and diplomatic documents to WikiLeaks. Her disclosures led to a series of exposes by the New York Times and many other outlets, and exposed, among other things, a dramatically high civilian death count in Afghanistan, evidence of abuse by U.S.-backed Iraqi forces, and information about who was being held at Guantánamo Bay.

In 2013, Manning was convicted of six counts of espionage by a military court, but she was acquitted of “aiding the enemy” — the equivalent of a treason charge in U.S. military court. President Obama commuted her sentence before leaving office in January.

The Canadian Embassy could not be reached for comment.

Jameel Jaffer, a Canadian free speech attorney with Columbia Law School’s Knight First Amendment Institute, said he was disappointed by the decision.

Obviously Chelsea Manning doesn’t present any danger to Canada’s security.  And isn’t it clear that Canadians, like Americans, would benefit from engaging her in discussion and debate?”

Top photo: Chelsea Manning is seated in the back of a vehicle as she departs The Nantucket Project’s annual gathering on Sunday, Sept. 17, 2017, in Nantucket, Mass.