"The simple situation is I have a year left on my contract and it is up to Tottenham whether they want to extend that or not," Redknapp told Sky Sports.
"It's not a case of me looking for security. What it's about is that when players know they have only a year left on their contract it doesn't work.
"You don't let players run into the last year of their contract if you think they are any good and you don't let managers run into the last year of their contract if you think they are any good," he added.
Redknapp has been with the Londoners since October 2008 and is happy with the progress Spurs have made in that time.
"Things couldn't have gone better," he said. "We've finished fourth twice, fifth once, reached the quarter-finals of the Champions League and played fantastic football.
"It's a good club and I enjoy being at Tottenham... [but] it's up to the chairman. If he doesn't want to give me another contract, it's his decision."
Although Spurs finished fourth last season, which usually brings a place in the Champions League play-offs, they missed out on Europe's elite competition after sixth-placed Chelsea won the trophy. UEFA allows a maximum of four teams from any country.
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