Halkett began playing for the South African national team in 2009. He competed at the 2010 Hockey World Cup in India, the 2010 Commonwealth Games in India, the 2012 Summer Olympics in England, the 2014 Hockey World Cup in The Netherlands, the Commonwealth Games. in Scotland. He is an African Cup of Nations gold medalist for 2009, 2013 and 2015. He won South African Men’s Player of the Year in 2016. After the 2018 World Cup he retired from the national team.