Iran's president called Israel a "war-mongering regime" Wednesday in condemning Israeli Prime Minister Benjamin Netanyahu's controversial address to the U.S. Congress.

"The time has passed when someone could change the public opinion of a nation or the world through rhetoric or a speech," Iranian President Hassan Rouhani said at his weekly Cabinet meeting. "Both - people of the world and Americans - are vigilant enough not to accept an advice-giving language from a war-mongering regime."

Rouhani said that Israel has "tainted the region" with nuclear weapons of its own that don't have to be inspected by international watchdogs.

Also Wednesday, U.S. Secretary of State John Kerry challenged critics of a nuclear deal being negotiated with Iran to come up with a better alternative, in a spirited rebuke to Netanyahu's claims that the emerging pact would leave Tehran just a step away from making atomic arms.

Separately, a senior U.S. official tamped down expectations of a formal, preliminary deal this month outlining constraints on Tehran's nuclear program in exchange for sanctions relief for the Islamic Republic.

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The talks are facing headwinds not only from critics in Congress who fear the U.S. may accept terms too lenient on Iran, but also from Netanyahu. He told Congress Tuesday that the agreement taking shape is dangerous and would allow Iran the ability to develop nuclear weapons.

But Netanyahu offered no alternate negotiating tactic beyond urging the U.S. to walk away from the table, a point Kerry noted Wednesday at the end of several negotiating rounds with Iranian Foreign Minister Mohammed Javad Zarif that he said made some progress.

If talks are successful, the deal being negotiated will "achieve the goal of proving that Iran's nuclear program is and will remain peaceful." Kerry said. "No one has presented a more viable lasting alternative for how you actually prevent Iran from getting a nuclear weapon."

His comments to reporters reflected U.S. concerns about the potential damage Netanyahu's speech could have on the negotiations' success by further empowering powerful Republican opponents in Congress who are threatening to scuttle any deal they deem lacking by pressing for new sanctions.

Last week, senators introduced legislation to give Congress a say over any deal, and Republicans are trying to get it passed even as the talks continue.

The U.S. official told The Associated Press the negotiations are aiming for a much looser construct of a deal than the framework originally planned - "an understanding that's going to have to be filled out with lots of detail" by their late March target date.

The official demanded anonymity because the person wasn't authorized to discuss the secret negotiations publicly.

Once Iran and the six nations negotiating with it reach such a point, President Obama will then determine whether there are grounds to continue talks aimed at a comprehensive deal in June, the official said.

Playing down the prospects of any damage caused by Netanyahu's speech, the U.S. official told the AP senior Israeli officials would be briefed by secure phone by top U.S. negotiators on the latest round.

Kerry also planned to share results of the negotiations with U.S. allies. He planned to meet with Arab Gulf state allies in Riyadh Thursday before sitting down with the foreign ministers of France, Britain and Germany in Paris on Saturday.