(CNN) Israel will not exist in another quarter century, Iran's supreme leader, the Ayatollah Ali Khamenei, said during a speech this week in Tehran, state-run media report.

"I'd say (to Israel) that they will not see (the end) of these 25 years," the Islamic Republic News Agency quoted Khamenei as saying Wednesday at the Imam Khomeini Mosque.

Khamenei raised the issue while discussing the recent nuclear deal between Iran and the so-called P5+1 -- the United States, United Kingdom, France, Germany, China and Russia -- by which, among other things, Iran agreed to cut its uranium stockpiles and centrifuges and limit uranium enrichment in exchange for the West lifting sanctions against the Islamic Republic.

The agreement allows the International Atomic Energy Agency to access Iranian facilities for verifications. Still, the Obama administration has faced fierce criticism over the agreement from both sides of the aisle , and especially from Republicans who have promised to scuttle the deal despite the fact the President reportedly has sufficient support to veto any such measure.

Khamenei's speech promises to make a contentious deal pricklier.

Some of the agreement's measures will remain in place for 25 years. Seizing on that time frame, Khamenei noted that some observers say it should allay Israel's fears about a nuclear Iran during that time.

"God willing, there will be no such thing as a Zionist regime in 25 years. Until then, struggling, heroic and jihadi morale will leave no moment of serenity for Zionists," he said, according to IRNA

After negotiations, in Zionist regime they said they had no more concern about Iran for next 25 years; I'd say: pic.twitter.com/dBA7oAbFPX — Khamenei.ir (@khamenei_ir) September 9, 2015

From London, where he is meeting with UK Prime Minister David Cameron, Israeli Prime Minister Benjamin Netanyahu took the opportunity to reiterate his opposition to the nuclear deal, saying that Khamenei's words leave its supporters with no "room for illusion."

"He has made it clear that the U.S. is the Great Satan and that Iran intends to destroy the state of Israel. This will not happen. Israel is a strong country and it will become even stronger," Netanyahu said in a statement. "However, the conclusion that arises from the remarks of the tyrant in Tehran is that all responsible countries must cooperate in order to stop Iran's terrorism and aggression which, to my regret, will only increase as a result of the agreement."

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Khamenei said during his speech that the nuclear negotiations will be the extent of Iran's dealings with the United States. He accused Washington of holding negotiations with Iran only so it can influence the country and impose its demands, he said, according to state-run Press TV.

"We agreed to hold talks with (the Americans) only on the nuclear issue and for particular reasons, and thank God, our negotiators did a good job," he said.

The Americans take a hypocritical approach toward Iran, the supreme leader alleged, saying, "One (U.S. official) smiles, while another draws up a bill against Iran."

The late Ayatollah Ruhollah Khomeini, whom Khamenei succeeded in 1989, always described the United States as "the Great Satan," Khamenei said. (Khomeini, an opposition leader who was forced into exile in 1963 , during the reign of U.S.-backed Mohammad Reza Shah Pahlavi, took power in 1979 after Pahlavi was himself forced into exile.)

"Some people insist on disguising this Great Satan as the savior angel. (However), the Iranian nation expelled this Satan (from the country); we must not allow that when we expelled it through the door, it could return and gain influence (again) through the window," he said.