England are "not a top-four team yet" but are "proud" they reached the World Cup semi-finals, says manager Gareth Southgate.
Southgate believes England have not reached their peak and can improve for the 2020 European Championship.
"We don't kid ourselves and we know the areas we hope to get better," he said.
"We are very proud of what we have done. Against the best teams we have come up short, but we have had a wonderful experience. I couldn't ask for any more from the players.
"We were 20 minutes from a World Cup final three nights ago."
Southgate led England to their first World Cup semi-final since 1990, a feat he admitted was "beyond what we thought was possible".
"I felt it was important to tell them how proud I was and to recognise how far they got," said Southgate.
"We haven't hidden in terms of where we see our progress, but we also leave here having progressed a lot as a team.
"The experiences the players have had and the enjoyment is important in an England shirt. They would have learned a lot in victory and in defeat, and now we look to the future."
England had the youngest squad in Russia, and Southgate hopes the "brilliant adventure" will help build "belief and momentum".
"But we are also very realistic about the constant improvements we have to make," he added.
"It has been nice to receive a lot of praise but, balanced with that, we have had a lot of reality as well."
England's next fixtures are in September, when they face Switzerland and the USA, before meeting Spain and Croatia in the Uefa Nations League in October.
Southgate said: "We have some big fixtures in the autumn so they are great opportunities for us to develop and improve, try things, look at players and constantly try to evolve."