Netanyahu has set out a mid-2013 "red line" for tackling Iran's uranium enrichment project. The West says this programme is aimed at developing the means to build atomic bombs. Tehran denies this, saying it is enriching uranium for civilian energy.
"Preventing Iran becoming a nuclear (threat) is, I would say, the central aim in my next term if I earn the confidence of voters," Netanyahu told Israel's Channel 2 in a recorded interview.
Opinion polls have consistently shown Netanyahu's rightist Likud Beiteinu party as the clear front-runner for the January 22 elections, meaning he would be called upon to form a new coalition government.
Since announcing elections on October 9, Netanyahu discussed Iran nuclear programme in public less frequently than he had before setting the "red line" in a speech to the United Nations General Assembly on September 27.
But he told interviewers that he was dealing with the issue on a daily basis.
"There is not a day on which I do not speak to foreign leaders about Iran, this was the case and it remains so," he said. (Writing by Ori Lewis; Editing by Jon Hemming)