Denmark's justice minister says a U.S. government airplane parked at Copenhagen's airport in June 2013 was waiting to fly former National Security Agency contractor Edward Snowden to the United States.

Soeren Pind said in a letter to Parliament Friday that the plane's presence "allegedly was to have been to be able to transport Edward Snowden to the United States in case he was extradited from Russia or another country."

Snowden, who was granted asylum in Russia, leaked millions of documents about U.S. government surveillance in 2013.

In the letter Pind regretted being unclear about the plane's presence in close U.S. ally Denmark when quizzed by lawmakers on Wednesday.

No other details were available as the case is deemed confidential.