It would be a "historic mistake" to ease pressure on Iran over its nuclear programme right now, according to Israeli PM Benjamin Netanyahu, BBC reported.
Opening parliament's winter session, Mr Netanyahu said Israel must "keep up the pressure" on Iran, "particularly at this moment".
His speech came on the eve of nuclear talks in Geneva between Iran and international negotiators.
Iran's foreign minister said he hoped a "roadmap" could be reached.
"Tomorrow is the start of a difficult and relatively time-consuming way forward," Mohammad Javad Zarif posted on his Facebook page.