England will search the world for the best head coach - RFU
The Rugby Football Union will not be "inhibited" in its search for the best possible successor to Stuart Lancaster as England head coach.
RFU chief executive Ian Ritchie did not rule out approaching a coach already under contract and said the cost of the "global search" was not important.
Lancaster, 46, left his position on Wednesday following a review into the team's early exit from the World Cup.
Ritchie said: "We're looking for a head coach with international experience."
England became the first sole host nation to be eliminated in the group stage of a Rugby World Cup, after defeats by Wales and Australia.
A review into England's performance followed, which involved an RFU panel taking "extensive feedback" from some members of the squad and all 12 directors of rugby at Premiership clubs.
Ritchie said the RFU's focus would now be on taking "sufficient time" to find the right person to succeed Lancaster.
"Speed is important, but the right person is even more important," said Ritchie, who added he was "confident" the RFU would get the best person for the job.
"It doesn't rule out a foreign coach, it doesn't rule out an English coach. The nationality is not important, getting the right coach is important.
"This is still one of the biggest jobs in world rugby coaching. The resources we put behind the head coach is significant, there's a group of talented players that the head coach has to work with and it is an attractive job."
Asked whether the RFU would consider approaching another union in search of Lancaster's successor, Ritchie said: "I don't think we should be inhibited."
What happens to Lancaster and his assistants?
The RFU said Lancaster, who signed a new six-year contract in October 2014, would leave the organisation.
Prior to taking charge of the national side in 2012, Lancaster coached England's second team - the Saxons - and oversaw elite player development at the RFU.
"For a new head coach, it's very difficult for the previous head coach to be sitting there within the organisation," Ritchie said.
"We did have discussions, we did look at this, but despite the skills Stuart has we felt it was right to make a clean break."
The futures of coaches Graham Rowntree, Andy Farrell and Mike Catt will be decided by the new head coach.
Ritchie added: "The assistant coaches remain under contract. The head coach will want to have look at what he's got."
'Time for a change'
Ritchie said it was mutually agreed that Lancaster would step down and the decision was "unanimously accepted" by the RFU board.
The five-man World Cup review panel helped decide his future after speaking to 29 people, while Ritchie talked privately with an additional 30.
Ritchie said every member of the squad had had an opportunity to give their feedback, as did the entire coaching and management team.
"The panel was rigorous and objective in looking at this information," said Ritchie. "We together concluded that it was a time for a change of head coach."
Who is being linked with the job?
The RFU said the search for Lancaster's successor began after Tuesday's board meeting.
But it denied reports that RFU president Jason Leonard has already made contact with Australia coach Michael Cheika.
Cheika, who is under contract until 2017, has transformed the Wallabies during his 12-month tenure, guiding them to the World Cup final, where they lost to New Zealand.
The 48-year-old Australian is the second high-profile name to be linked with the role after Nick Mallett said in October he had turned down an approach. Again, the RFU denied the former South Africa and Italy coach had been sounded out.
Bath's English coach Mike Ford, who has international experience as an assistant coach of both Ireland and England, has ruled out the prospect of taking over from Lancaster.
The key decision-makers
The "global search" for a new head coach will be carried out by Ritchie, a trained barrister responsible for extending Lancaster's contract last year.
The decision to offer Lancaster a new deal has been criticised by many, with World Cup-winning coach Sir Clive Woodward saying last month that Ritchie should "not be allowed anywhere near" the review panel.
But RFU chairman Bill Beaumont said the former All England Club chief executive had the full support of the board.
"I've every confidence in Ian as chief executive to deliver the best international coach for English rugby," said the former England forward.
Ritchie, who has also been a director of both the Football League and Wembley Stadium Ltd, said an advisory board would not be formed but that he would talk to a number of people involved in the game.
No rethink on overseas-based players
The RFU only allows players from overseas clubs to be selected for the national team in "exceptional circumstances".
Toulon open-side flanker Steffon Armitage, the 2014 European Player of the Year, was the most high-profile World Cup omission on those grounds.
It is a policy that has been described as "criminal" by Clermont's English full-back Nick Abendanon.
Australia revised their policy before the World Cup, but the RFU has no plans to follow suit.
"That is the current arrangement and agreement," said Ritchie. "I think that is right. I don't think that was an impediment to what happened in the Rugby World Cup."