Niño Guerrero was killed in a “swift and lethal kinetic strike,” the US President wrote in a social media post.
World Cup kicks off in the US with performances from Katy Perry, Future and Tyla
Earlier, Canada hosted its own opening ceremony in Toronto, featuring singers Alanis Morrisette and Michael Bublé.
Watch: Why is Trump not at the World Cup?
All three leaders of the North America host nations have missed the tournament opening matches.
Deal to end fighting would lead to Hormuz reopening, Iran says
The deal which will pave the way for hostilities to end is close to being finalised, the US, Iran and mediators Pakistan say.