London - England's fourth consecutive runners-up finish in the Six Nations was "not acceptable", Rugby Football Union (RFU) chief executive Ian Ritchie told reporters on Tuesday.
England narrowly lost out to Ireland on points difference after a thrilling finale to the tournament on Saturday, but Ritchie says they cannot accept second-best in a year when they host the World Cup.
"Four years as runners-up is not acceptable and we are not happy with how that came about," Ritchie said.
"If you go back through history, bearing in mind a lot of things, we should be, as a country, winning more in terms of Grand Slams, Six Nations championships, other things."
England fell six points short of the title after a stirring 55-35 victory over France, and Ritchie felt the damage had been done earlier in the tournament.
"We had opportunities," he added. "Let's be clear -- entirely in our control. It was stuff that was in our own hands. The Irish deserved the win because of what they did over the five matches.
"We did not do enough over the five matches. There's no point in bleating about it.
"We simply didn't take opportunities, didn't do what we should have done, were not clever enough during parts of the game in order to deserve to win."
While there is no suggestion that Stuart Lancaster's position as head coach is under threat, Ritchie warned that the time for experimentation was now at an end.
"'We're developing, this is a development opportunity' -- I don't take that," he said. "I don't think we're in a development phase. We should be going into every game, doing our utmost to win and to win well.
"We've got the resources, the talent, the ability. Saturday was a fantastic example of that. We've got to make sure we come out for the World Cup and deliver."