"It's something I'd be interested in if there was a door there," he said.
Brotherton joined North Carolina in 2019 and made 44 first-team appearances across two seasons at the USL club. He spent the previous two years at English side Sunderland, playing in the under-23s.
"The USL is a market I've played in for the last two years, and I'm familiar with," said Brotherton.
"It's somewhere I feel I have a decent reputation. I think over the past two years I've proven myself as a good player in this league.
"I enjoy playing and living in the US, so it's definitely an option to move to another club here, but I'll also explore other options around the world, evaluate, and see where hopefully I can find a good fit.
"It's about finding the right environment where there's a good level, so I'm going to be challenged but also play consistently. I'm open to all opportunities," he said.
Brotherton grew up in Auckland, playing his junior football at Forrest Hill Milford and attending Westlake Boys High School. He played for Western Springs, Central United and the Auckland City youth side before heading offshore.
Brotherton was part of the New Zealand team that made the knockout rounds at the 2015 under-20 World Cup played on home soil, scoring his first international goal against Myanmar in Wellington. Later that year he made his full All Whites debut and was an ever-present as New Zealand won the OFC Nations Cup in 2016.
The most recent of his dozen caps came in a four-team tournament in India in 2018.
"It's still a huge motivation of mine," Brotherton said of his international aspirations.
"When you look at 2026 and the way (automatic World Cup) qualification is working, I'd like to think I'd still be involved in the game and be at a good age.
"It's something I definitely have on my horizon and keeps the fire burning inside."