Israeli Prime Minister Benjamin Netanyahu said on Sunday that Iran is capable of converting low-grade uranium to weapons-grade within weeks.
"Iran is prepared to give up enriching uranium to 20 percent and therefore debate on this subject is unimportant," Netanyahu's office quoted him as saying at a weekly meeting of his cabinet.
"The important part stems from technological improvements which allow Iran to enrich uranium from 3.5 percent to 90 percent in a number of weeks.
"Pressure on Iran, which continues enrichment while negotiating, must be intensified," the Israeli leader added.
Iran's nuclear enrichment programme is at the core of its dispute with world powers, who suspect it masks a drive for atomic weapons despite repeated denials by the Islamic republic.
Iran is to hold a new round of talks on the issue with six world powers in Geneva on November 7-8.
Israel has repeatedly warned against the so-called charm offensive of Iran's new President Hassan Rouhani, which led to direct talks between Tehran and the P5+1 countries -- United States, Britain, France, China and Russia plus Germany -- in Geneva on October 15 and 16.
The Jewish state, the Islamic republic's arch-foe, has insisted there be no relief for Iran from crippling economic sanctions which brought it to the table in the first place.
Israel, the Middle East's sole if undeclared nuclear-armed power, wants Iran to meet four conditions before the sanctions are eased: halting all uranium enrichment; removing all enriched uranium from its territory; closing its underground nuclear facility in Qom; and halting construction of a plutonium reactor.
Netanyahu has said Israel reserves the right to launch unilateral military action against Iran if necessary to stop it developing the ability to build a nuclear bomb.