The 21-year-old, who was born in Brussels to Italian and Spanish parents, played for Belgium at junior level. Yet in 2024, he chose to play for Spain but subsequently did not honour a call-up to their under-20 side.
Fernandez-Pardo has had a strong season at Lille, who sit third in Ligue 1 and are on course for a place in next season’s Champions League, and is seen as an option up front where Belgium have concerns.
All-time top scorer Romelu Lukaku has had an injury-plagued season and featured little for Napoli, while Lois Openda has played little at Juventus, prompting the Belgian federation to approach Fernandez-Pardo.
"Choosing Belgium wasn't easy because I feel a deep connection to both Belgium and Spain,” said Fernandez-Pardo in a federation statement on Tuesday.
“The positive and sincere discussions with (coach) Rudi Garcia and (Belgium football association technical director) Vincent Mannaert ultimately played a decisive role in my decision to choose Belgium.
“Furthermore, playing alongside my teammates Thomas Meunier and Nathan Ngoy at Lille reinforced my decision,” he added.
“They helped me solidify this feeling, both on and off the pitch. I'm delighted to now be able to fully commit to the Belgian national team."
Garcia will name the 26-man Belgium squad for the World Cup on Friday. They take on Egypt, Iran and New Zealand in their group at next month’s tournament in Canada, Mexico and the U.S.