Pozniak has been capped by Canada at the U20, U23, and senior levels. He competed in the 2001 FIFA World Youth Championship in Argentina. His first senior cap for Canada came in the 2002 CONCACAF Gold Cup against Haiti as a late game substitute. He has since earned a total of 24 caps, scoring no goals, and become an important contributing member for Canada's squad. He has represented Canada in 3 FIFA World Cup qualification matches.