White House spokesman Jay Carney downplayed any new tension between Iran and the U.S. after President Obama's meeting with Israeli Prime Minister Benjamin Netanyahu on Monday.

On Monday evening Iranian Foreign Minister Javad Zarif took to Twitter to accuse Obama of imposing illegal sanctions and of doing a “flip flop” on his willingness to engage in talks about containing Tehran's nuclear program.

“Pres. Obama's presumption that Iran is negotiating because of his illegal threats and sanctions is disrespectful of a nation, macho and wrong,” Zarif tweeted.

“President Obama needs consistency to promote mutual confidence. Flip flop destroys trust and undermines US credibility,” he wrote in a second tweet.

Zarif’s comments came after Obama and Netanyahu met Monday and touted crippling international sanctions against Iran, saying they had helped bring Tehran to the negotiating table.

Carney on Tuesday defended the sanctions regime.

“The implementation of those sanctions in turn has led, in part, to where we find ourselves today, which is with a new government in Iran that has indicated willingness to negotiate a solution to this problem diplomatically,” Carney told reporters.

Although words are meaningful, ultimately, “actions are most meaningful,” he added of forthcoming nuclear talks.

“It is only through verifiable, transparent resolution of this challenge, where the international community can be confident that Iran has given up its nuclear weapons ambitions, that we can get resolution, and the president will be very firm on that,” Carney said.

Iranian President Hassan Rouhani made a number of diplomatic overtures to the U.S. following his election. Last Friday, Obama spoke to him by phone — ending a three-decade freeze between the leaders of the two countries that began during Iran’s 1979 revolution.

Obama has directed Secretary of State John Kerry to begin talks with Iran on its nuclear program, which the west says Tehran is using to build weapons.

The move though has sparked concern on Capitol Hill and from America’s ally Israel, with critics fearing Iran is stalling for time as it develops nuclear arms.

During Netanyahu's sit-down meeting with Obama on Monday, the Israeli leader warned the U.S. not to ease sanctions against Iran and labeled Rouhani's latest diplomatic push a “smiley campaign.”

He said the U.S. should not be duped by Iran, arguing that Iran's “conciliatory words” have not been met by “real action.”

Obama, sitting alongside Netanyahu, concurred, noting that words are “not sufficient” and he and other Western leaders would demand “action.”

Before boarding his flight to the U.S., Netanyahu told the Israeli press: “I will tell the truth in the face of the sweet talk and the onslaught of smiles.”

He remained unconvinced on Tuesday, going before the United Nations to throw cold water on the notion that Rouhani is a moderate who can be trusted.

“Rouhani doesn’t sound like [Mahmoud] Ahmadinejad,” Netanyahu said, referencing the hardline Iranian president whose term ended earlier in the year. “But when it comes to Iran’s nuclear weapons program, the only difference between them is this: Ahmadinejad was a wolf in wolf’s clothing. Rouhani is a wolf in sheep’s clothing.”

Iran, Netanyahu said, is trying to convince Obama to jettison sanctions in response to mere assurances that Tehran will stop developing its nuclear program while maintaining its ability to go back to it at a moment's notice.

“Rouhani thinks he can have his yellowcake and eat it too,” Netanyahu said.

Sen. John McCain, R-Ariz., on Monday said he had talked to Netanyahu over the weekend and shares his deep concerns about the path the U.S. is taking with Iran.

“So far, all it's been is talk,” he told the Washington Examiner. “[Rouhani] is the same guy who fooled everybody while the number of centrifuges went from 150 to 1,000.”

“Don't trust, verify,” McCain added.

Any efforts by Tehran to convince the U.S. that its nuclear capability is for peaceful purposes only is not borne out by the facts, McCain argued.

“They've already enriched far beyond that ... so I hope we're not going to be buying that,” he said. “If they believe that, I've got some beach-front property in Arizona to sell them.”

Senate Intelligence Committee Chairwoman Dianne Feinstein, D-Calif., was equally adamant about seeing what the talks with Iran can produce.

“I think what's happening with Iran now is a breath of fresh air,” she said.

“There's a president and foreign minister who are prepared to sit down and work it out. What really upsets me is that a certain section of people on both sides are immediately throwing rocks at it,” she added.

Talking with Iran has yet to yield anything, Feinstein acknowledged, but she said it's important to be conversing.

“For people to talk that the odds are they can't solve the problem – well, they definitely can't if they're not talking,” she said.