"We got put into groups of three, we were assigned a country and we'd dress up in their national dress and those sorts of things," he said. "I did that all five years at school, it was really enjoyable."
Mr De Jongh also went to the National Model United Nations in Wellington.
"After having all of that kind of experience, I was really excited to try something new and sort of on a more challenging level," he said.
While in the US, the group visited universities Stanford, UC Berkeley, Harvard, MIT and Yale. They attended two conferences, one at Yale University and one at the University of Pennsylvania.
"We were all assigned a country or a position, then put into a committee and then for four days we had committee sessions and workshops," Mr De Jongh said.
"Then we discussed issues, debated and made changes. Essentially it's just representing the ideas of your country or your person and in the end you vote on it all."
He said that the experience was invaluable.
"I met lots of people and made lots of friends. We had a lot to do, but there was also a bit of freedom to explore for ourselves," Mr De Jongh said. "I had a really good time and learned a lot."