England head coach Eddie Jones has pledged to help build a "sustainably successful team" after extending his contract until 2021.
Jones was due to step down after the 2019 World Cup, but, having overseen a remarkable run of 22 wins from 23 Tests, his bosses have decided to lengthen his reign while inserting into the terms of the deal a performance break clause after Japan 2019.
The Rugby Football Union sees the contract extension as part of the succession planning for Jones' departure and hopes to have appointed his replacement by the end of the 2019-20 season. The two will then work together until Jones' exit.
"I'm delighted to extend, it's quite exciting," Jones said. "The team's got a great potential and what I'd also like to be involved in is creating a sustainably successful team and play a role in doing that.
"The first priority is to win the World Cup and after that making sure the guy who is going to take over has a good team to be involved in, has a good structure and hopefully I can play a role in ensuring that happens.
"It's quite a unique situation in world rugby to be able to do this and I'm delighted to be able to take a part in this process."
When asked if he would want to stay beyond 2021, the Australian added: "I think that's probably enough for me and a good opportunity to bring another coach through.
"That's the great opportunity of this situation and make sure they come through with a successful team and keep making England successful."
England open their Six Nations title defence against Italy on February 3 but will be without flanker James Haskell, who has been banned for four weeks for a dangerous tackle in the Champions Cup.
Jones is expected to name his squad on Thursday as the 2003 world champions attempt to make it a hat-trick of Six Nations wins.