The Oasis guitarist sparked a war of words earlier in the year when he said the US boy band "can't sing, can't dance, can't play".
He attacked their songs as "rubbish" and said they "should be shot".
But the Florida-based act have retaliated, just as Oasis visit America on their Brotherly Love Tour with rock group The Black Crowes.
Singer AJ McLean said of the Manchester-born songwriter: "He should just go back to London".
Fellow Backstreet Boy Kevin Richardson added that Gallagher's "opinion doesn't mean anything to us".
'Strung out'
The pair are currently on their own tour, playing dates across Latin America, with fellow band members Brian Litrell, Howie Dorough and Nick Carter.
Speaking in Caracas, Richardson added: "When Oasis came and performed at the MTV awards in the United States, he was spitting on the stage and it looked like he was all strung out on something.
"The only thing that matters for us is if we're happy with our music and if our fans are happy."
Oasis are infamous for starting rows with other musicians.
At the height of the Britpop era, Noel and Liam Gallagher were locked in a heated war with Blur, culminating in a chart battle between their two singles in August 1995.
Side swipe
Blur triumphed with the number one hit Country House, while Oasis' Roll With It entered at number two.
Liam and Robbie Williams made the headlines with very public displays of loathing.
Williams topped off the argument by offering to fight Liam at the Brit Awards in 2000.
But the Gallaghers are also notorious for constantly arguing among themselves.
Noel quit their European tour last year after arguments broke out, leaving the rest of the band to continue without him.
He said his younger brother had become too big for his boots.
Early in the band's career, a British music journalist released a recording of a bust-up between the brothers as a single, Wibbling Rivalry, which became a minor chart hit.