The Spaniard also believes that his squad could do with an injection of seasoned professionals who know what it takes to deliver results in a fiercely competitive Sky Bet Championship.
Those charged with the task of bringing in new recruits will be doing all they can to get the required bodies on board, with Karanka confident that chairman Steve Gibson will continue to provide unwavering support.
He said in the Evening Gazette: “To play here in the Championship you need strong players, with strong characters, who know the league and the culture.
“Yes, the shape of the team is built. We have had 15 clean sheets this season, so you can see that the basis of a successful team is there.
“Now, we have to address the positions where we have had problems this season in the full-back and strikers. We know that. Everyone at the club is working very hard to get the players we want.
“The first thoughts are to strengthen the squad because we are challenging with the better teams in the table like Derby, like Brighton and if we strengthen the squad, then we have more chance of achieving our objectives.
“And the chairman’s ambition and my ambition, the ambition of everyone at the club, is to win promotion to the Premier League.
“But it is easy to say ‘we will do this’. We have to be careful because the first thing is to know the squad we have and know the squads the other clubs have.
“After pre-season we can speak with more knowledge and more about the objectives.”