Martinez was asked about his future in the wake of the loss, but the Spaniard insisted that Saturday's third-place playoff against either England or Croatia is the main priority at present.
"It's too early to make any assessment for the tournament," Martinez told reporters after the game.
"We need to focus on the final game and fight for third place. Then we'll regroup. We need to look at the younger generation and try to be stronger for the future. We have a wealth of young talent coming through.
"It is a difficult emotion to manage – you are disappointed at losing a semi-final. The next 48 hours will be important. To try to finish third in a World Cup doesn't happen too often. It's an important game."
Belgium's previous best finish at a World Cup was fourth at Mexico 1986.