Stephen Kenny says he's "perfectly happy" with the arrangement which will see him take over from Mick McCarthy as Republic of Ireland manager in two years' time.
Kenny will manage the U21s and oversee the underage set-up in the interim, while McCarthy leads Ireland through the Euro 2020 campaign.
The handover is scheduled to take place in August 2020 and the five-time League of Ireland winner believes it's a good deal for both parties.
"It's an arrangement that I'm perfectly happy with. I'm delighted with it and I'll work extremely hard to do it justice," he said.
"I can't wait to get started.
"It's a huge privilege to be named U21 international manager and to be here for the next four years and beyond."
He said the deal was finalised on Saturday and he met McCarthy last night.
"The senior team is not my brief. My role is to support and assist the other Irish managers and work on developing and nurturing the next group of talented players.
"I've a lot to learn and the next two years gives me an opportunity to see other international teams, the tactical nuances of the systems and the detail of the blocks of two games for best practice in preparation."
FAI High Performance Director Ruud Dokter said: "We are delighted to bring Stephen in as Under-21 manager and to support me overseeing the underage international teams.
"Stephen has proven himself to be one of the best managers in Irish footballing history and his experience, enthusiasm and expertise will undoubtedly benefit Irish football going forward."