The Foo Fighters are taking a breather, but founder Dave Grohl clarified that the Grammy-winning rock band is on hiatus, not ending.

During a performance in New York last Saturday, Grohl told the crowd he didn't know when the band — now in its 18th year — would play again, fuelling rumours of a break-up.

On Tuesday, he issued an open letter to shine more light on the situation.

"I'm not sure when the Foo Fighters are going to play again. It feels strange to say that, but it's a good thing for all of us to go away for a while. It's one of the reasons we’re still here. Make sense?" he wrote.

"There were times when I didn't think the band would survive. There were times when I wanted to give up... [But] I can't give up this band. And I never will. Because it’s not just a band to me. It's my life. It's my family. It's my world."

Grohl noted that he's currently working on what could be "the biggest, most important" project of his career: a documentary and accompanying album about Sound City Studios, the iconic rock and roll recording and mixing studio in Los Angeles that has hosted acts from Neil Young to Fleetwood Mac to Tom Petty to Metallica.

Former Nirvana drummer Grohl formed Foo Fighters in Seattle in 1994, following the death of former bandmate Kurt Cobain. The alt-rock band's membership has shifted over the years, with the current lineup comprising Grohl, Nate Mendel, Pat Smear, Taylor Hawkins and Chris Shiflett.

Critically and commercially successful over the years, the band has won 11 Grammy Awards, including the best rock album title for the albums There Is Nothing Left To Lose, One by One, Echoes, Silence, Patience & Grace and 2011's Wasting Light.