HONG KONG — A human rights lawyer who represented the former N.S.A. contractor Edward J. Snowden when he fled to Hong Kong says pressure from the local authorities, the bar association and legal aid groups have made it impossible for him to keep working in the semiautonomous Chinese city.

The lawyer, Robert Tibbo, is a Canadian national who left Hong Kong last year and is currently living in France. He did not disclose his move for nearly a year, fearing it would harm the cases of his clients in Hong Kong, particularly asylum seekers who sheltered Mr. Snowden during his 2013 stay.

Mr. Snowden, who leaked top-secret information on United States surveillance programs that had monitored the communications of hundreds of millions around the world, faces charges in the United States, including two counts under the Espionage Act. He now lives in exile in Russia.

The revelation in September 2016 that Mr. Snowden had stayed with asylum seekers brought international attention to the status of such people in Hong Kong, where they are unable to work, are ineligible for permanent residency and face minuscule odds of being approved for resettlement in a third country.