The 30-year-old, who has impressed in his country's two World Cup games, joined the Spanish side on loan from Porto in January, scoring twice in 18 appearances.
Layun has yet to hear from Sevilla about a permanent deal, though he stated it would be "a dream" to continue his career in Andalusia.
"I'm just like everyone, waiting for something to be confirmed," he told Cadena SER.
"In a tournament like the World Cup I'm totally focused on what I want to achieve here, but of course there is always that issue of not knowing what will be of my future.
"Participating at such an important club in Europe was very special. I expressed that it would be a dream to be able to continue with the team.
"I still haven't ruled out the possibility of staying at Sevilla, because for me it would be very nice.
"It's complicated. But I think if they had the intention [to sign me] they would have already communicated with me and with my agent."
Layun will likely feature for Mexico in their final Group F clash on Wednesday against Sweden, where they need just a point to qualify for the last 16 as winners of their pool.