The 23-year-old cross-code convert represented Samoa in rugby league before his move to Sale.
He is also eligible for New Zealand, having been born and raised there.
"Obviously I'm enjoying playing here. I've been here for three years and it's the choice I want to make," he said.
"I confided in my coach and my family and they support me."
A court case is currently ongoing in which Super League side Castleford are suing Solomona, Sale and his agent Andy Clark over his move to the Premiership side.
Solomona, who grew up playing rugby union in Auckland, moved to England in 2014 from Australian rugby league side Melbourne Storm when he joined then Super League outfit London Broncos, before moving to Castleford Tigers after one season.
He has scored 11 tries in 11 appearances for the Sharks since his controversial cross-code move on a three-year deal from Cas, prompting reports he could play for the Lions in New Zealand this summer.
But, having not played international rugby union, Solomona's more likely first recognition could be on England's tour to Argentina in June.
"I just want to focus on what I need to work on and that's here at Sale. If England comes this summer, it comes, if it doesn't, it doesn't," he told BBC Sport.
"There is always next year or the year after, but at the moment I'm trying to enhance my skills as a rugby union player."
Solomona was contracted to Castleford until 2018 when he moved to the Sharks, and unhappy fans have given Solomona personal abuse on social media after it was claimed he resigned from rugby league.
"That's what comes with the job," Solomona said. "If you're not hated, you're not doing something right - simple.
"The Sale coaching staff have been really good and they've helped me with the background stuff to help me block it out with what I need to do on the field.
"Playing is a release for life - if you go out there you can forget everything and you can focus on one thing and that is to win."
Asked if he can understand Castleford's frustrations, he responded: "100%. Everyone has their frustrations and problems but life moves on.
"We're months out from it now, I've moved on and I'm sure they'll move on too."
Sale Sharks winger Denny Solomona has declared himself available for England after completing his three-year residency period and signing the relevant paperwork.