The 23-year-old has been linked with a possible call-up from Three Lions boss Sam Allardyce following a bright start to life in the Premier League.
However, Karanka only wants his star centre-half to place emphasis on Boro's next top flight future, which takes place at home against Tottenham Hotspur on Saturday, rather than think about his international career.
"Ben has to focus on his job, playing games here," the Boro manager said.
"He has an important game against Tottenham here this Saturday and it could be his worst mistake to start thinking about the national team when he's only played five games in the Premier League. But he's a calm lad so I think and I know he'll remain calm and he'll be just thinking about the game on Saturday.
"If he's on the England list next week then we can celebrate but at the moment the main thing to think about is Tottenham. He has to help us to win games here and then he can think about the national team."