Kevin de Bruyne says Belgium have to “be better in every way” after they were beaten comfortably by France in the Nations League on Monday.
The Manchester City midfielder said he had let his team-mates know “what went wrong” during a charged exchange at half-time.
Belgium are third in League A Group 2, level on three points with France.
De Bruyne conceded the side are not as good as they were in 2018, when they reached the semi-finals of the World Cup, but added: “Other things are unacceptable. I’m not going to say what.”
Belgium opened their Nations League campaign with a 3-1 win against Israel - with De Bruyne scoring twice. But after starting brightly against France, they fell behind to goals by Kolo Muani and Ousmane Dembele.
Speaking to Belgian broadcaster VTM after the 2-0 defeat, De Bruyne would not elaborate on what was said during his half-time team talk.
“I cannot repeat that in the media but it has to be better in every way,” said the 33-year-old.
“If the standard we want to reach is the best, but we’re no longer good enough to get to that level, then you have to give everything.
“If you don’t even do that, it’s over.”
De Bruyne did, however, highlight what he feels is a weakness in Belgium’s style of play.
“If you stay with six at the back, there is no connection,” he added. “It is what it is.
“It is not about transition, but about people who do not perform their tasks.”
Belgium head coach Domenico Tedesco said he could see why De Bruyne was frustrated with the performance.
“He is our captain and has a huge winning mentality, so he can also react emotionally,” said Tedesco.
