Leading Swiss tennis player Lulu Sun has switched national allegiance and will represent her native New Zealand, to immediately become the country's top-ranked player.

Te Anau-born Sun is ranked at a career-high 151 and confirmed she would play for the country where she grew up before leaving for Switzerland as a young child.

The 22-year-old said she always cherished her connection to New Zealand, with her grandparents still living in Te Anau, and that feeling grew stronger after competing at the ASB Classic in Auckland in January.

She reached the second round of the tournament and during her visit met with Tennis New Zealand New Zealand officials to discuss a switch of allegiance.

The International Tennis Federation signed off on her swap and Sun will be a key figure in the New Zealand Billie Jean King Cup team for the Asia/Oceania Group One event in China in April.

There is also the potential for Sun to partner with Erin Routliffe in the doubles at the Paris Olympics in July.

"After deep reflection, it is with great pride that I announce my commitment to represent New Zealand, my birth country, on the international stage at the upcoming Billie Jean King Cup," Sun said in a statement.

"This decision is a truly pivotal moment in my career and a heartfelt tribute to my origin.

"Born on the South Island, my journey took an international turn at a young age when I moved to Switzerland.

"Throughout the years, my deep bond with New Zealand has remained, and many of my favourite memories have involved spending time amidst the natural wonders of New Zealand with my extended family."

Lulu Sun serves in her match against Varvara Gracheva of France during the 2024 Women's ASB Classic in Auckland. Photo: Photosport

Sun briefly represented New Zealand as a junior to play at Wimbledon in 2018 but it had seemed likely she would continue to represent Switzerland on the world stage.

"Participating in the Auckland Open this past January was a transformative experience. The overwhelming support and feeling of being embraced by an entire country strengthened my deep connection to New Zealand and my sense of 'being home'," she said.

"Growing up in Switzerland and spending my formative years there has led me to carry love for both countries in my heart.

"I feel an incredible love for Switzerland and a sincere gratitude for the Swiss tennis community for their support and opportunities.

"Representing New Zealand is more than a professional choice; it is a tribute to my roots, a celebration of my origin, and a commitment to the country that has always been a fundamental part of who I am and who I want to become."

Sun backed up her run at the Classic, by winning through qualifying at the Australian Open and took the title last month at an ITF tournament in Roehampton, England.

She has never contested the main draw of any grand slam tournament but some strong results over coming weeks could see her automatically make it into the main draw at the mid-year French Open and Wimbledon grand slams.

Having climbed 63 places in the rankings this year, Sun is comfortably New Zealand's highest-ranked singles player, surpassing Monique Barry at 650, while the top men's singles player is Rubin Statham at 557.

Tennis NZ chief executive Julie Paterson said it was great outcome for the sport locally.

"It was fantastic to see Kiwi tennis fans support her so well at the ASB Classic and there is no doubt this helped motivate her decision," Paterson said.

"Lulu, alongside Erin, will be leaders for women's tennis in New Zealand for years to come and help inspire and guide the next generation of talent coming through.

"We're incredibly excited for what the next few years will bring."

Former top 40 player and Tennis NZ board member Marina Erakovic echoed Paterson's sentiments.

"I am very excited to have Lulu play for New Zealand," Erakovic said.

"She is a young player that has a game with a lot of potential, she has a good team and setup already which has seen her nearly break that top 150 mark.

"Lulu will be a great addition to the Billie Jean King Cup team and I am excited to see what the future brings for her under the New Zealand flag."

Reproduced with permission