Vice Prime Minister Silvan Shalom made the comment on the day that Iran announced it was still studying a U.N.-drafted plan to ship much of its uranium to Russia and France for further enrichment, a move seen as a way to delay the country's ability to build a nuclear weapon.
Iran's envoy to the U.N. nuclear agency said the government will respond to the offer next week.
Shalom, who is also the minister for regional development, said he discussed Iran's nuclear ambitions with U.N. Secretary-General Ban Ki-moon during a discussion that also included Israeli-Palestinian peace prospects and Lebanon.
"I told the secretary-general that we were very concerned that Iran will use the goodwill of the international community to continue to develop their real intentions — and it is toward nuclear power on the one end but on the other end to try to change the types of the regimes within the Middle East," he said.
The six world powers trying to ensure that Iran's nuclear program remains peaceful held talks earlier this month with Iranian diplomats, despite a spike in tensions over September's revelations by Iran that it had been secretly building a new uranium enrichment plant near the holy city of Qom.
The meeting — and tentative agreement on the plan to ship out much of Iran's low-enriched uranium — indicated a willingness on both sides to talk.
But Israel, which has been threatened with annihilation by Iran's President Mahmoud Ahmadinejad, is clearly unhappy.
"We believe that Iran will never abandon their dream to become a nuclear power," Shalom said. "They hide their real intentions in the past, and they will do it in the future."
He singled out the recent disclosure about the nuclear facility at Qom.