Asked about his future following the tournament, 52-year-old Martinez acknowledged that his contract expires following the World Cup, but that he was "focusing on finishing the work we have started three-and-a-half-years ago".
"This is not news, we have talked about this a lot in Portugal," Martinez said. "The most important thing is to focus on winning the World Cup."
Martinez will be without centre-back Ruben Dias against Congo after the defender failed to recover in time from a knock sustained in Portugal's friendly against Nigeria.
"Medically we need him to be at 100% for a World Cup match and that is how we will proceed. It is about not taking risks at this stage of the tournament," Martinez said.
But he will have Cristiano Ronaldo, who features in a sixth World Cup, though Martinez said it felt as though it was the Portugal forward's first.
"He is a role model, he is an iconic player in global football for athletes, male and female, who love football. It is his sixth World Cup, but it feels like his first one when it comes to the intensity with which he works.
"He is essential, he is a striker who can open up spaces for others in the team."
Martinez is expecting a tough encounter against Congo, who are physical and quick on the transition. He said they will underestimate the African side at their peril.
"We need to match the emotions of Congo. If you win by one goal, it is just OK, if you draw it is a catastrophe, and if you lose it is the end of the world.
"Cape Verde have shown there are no easy games in this World Cup," he added after the debutants drew 0-0 with European champions Spain in their opening game on Monday.
Captain Bruno Fernandes said Portugal will play with former teammate Diogo Jota in their thoughts. The forward was killed in a car accident last year and would likely have been an important part of the team at this World Cup.
"Everyone has spoken about him," Fernandes said. "He was a great teammate, very down to earth, very passionate about what he could do for our country and football as a whole.
"For us, he is still part of our group."
