CNBC | Patti Domm: Crude prices are likely to be volatile and higher, as tensions between the U.S. and Tehran rise ahead of the next wave of sanctions, aimed at cutting off Iran's oil exports by early November.

As a�first wave of U.S. sanctions were reimposed�Monday on Iran's financial, automotive, aviation and metals sectors, Iran President Hassan Rouhani lashed back, saying President�Donald Trump's call for talks between the two countries was not honest and was only for show in America.

"If you stab someone in the back and then say you want talks, then the first thing you have to do is remove the knife," Rouhani said in a televised address. Rouhani's speech came after reports of protesters taking to the streets in recent days complaining about the faltering economy and rising prices, and chanting: "Death to inflation! Death to unemployment!" according to�The Wall Street Journal.

Analysts see little chance for discussions between the U.S. and Iran and expect both sides to become more entrenched, for now.

"There's no way there's sanctions relief before an agreement is reached. Then the Iranians don't gain anything from talking," said Matthew Reed, vice president at Foreign Report. "The White House has set a very high bar for what they think Iranian conduct should be. This is not just about the nuclear agreement. It's about everything the Iranians do and get away with in the region."

The U.S. has objected to Iranian meddling in the conflicts in Syria and Yemen, in which it supports rebels that are hostile to Saudi Arabia. The U.S. has also charged that Iran supports terrorist organizations such as Hezbollah and Hamas. "On top of that, the White House also wants to see human rights respected. It's a very long list and a lot of it speaks to the DNA of the [Iranian] system," Reed said.

Oil prices were higher Monday�as the sanctions were reimposed but mainly because Saudi Arabia oil production reportedly fell in July, to 10.29 million barrels a day, a decline of 200,000 barrels from the month earlier. The decline in output was a surprise because Saudi Arabia had seemed to commit to�Trump's request to tap its spare capacity and add barrels�to the market to make up for shortfalls due to Iran.

The reduction in Iranian exports has not yet shown up in the market, but the Saudi reduction in output created nervousness in the market. "Without the extra Saudi oil we had in June, it's hard to crunch the numbers and get a lower price going into the end of the year," said John Kilduff of Again Capital, adding Saudi Arabia should now be gearing up to increase its output.

West Texas Intermediate crude futures�rose 0.8 percent Monday to $69.01 per barrel. How much oil prices move in coming weeks though depends on how successful the U.S. will be in halting Iranian oil sales around the world by Nov. 5, when another round of sanctions hits Iranian oil exports. Analysts expect as much as 1 million barrels a day to come off the market by year-end or the first quarter, while the U.S. had demanded that all Iranian exports of about 2.5 million barrels a day be stopped.

"From all I'm hearing, the Trump administration is very serious about efforts to deeply cut Iranian exports and put more pressure on the regime, and I do think this market will tighten," said Helima Croft, head of global commodities strategy at RBC. "In the fourth quarter, we will have a much tighter situation. On price, it will be how much can Gulf States respond in terms of putting additional barrels on the market and what do security issues look like. Are we having an Iranian nuclear restart or are we having maritime issues?"

U.S. officials have said they want Iranian exports to drop to zero by November though they have also said they will talk to countries and companies that are trying to cut back.

"I am pleased that many international firms have already announced their intent to leave the Iranian market, and several countries have indicated that they will reduce or end imports of Iranian crude oil. We urge all nations to take such steps to make clear that the Iranian regime faces a choice: either change its threatening, destabilizing behavior and reintegrate with the global economy, or continue down a path of economic isolation," Trump said in a statement Monday.

The Trump administration withdrew from the nuclear deal with Iran and five other countries that had ended sanctions on Iran in return for it terminating its nuclear program. The Trump administration said the deal favored Iran and would have allowed it to resume its nuclear program eventually. The other countries so far remain in the deal with Iran but�there is some speculation Iran will return to its nuclear program,�after Europe proves unable to take actions to soften the blow of the sanctions.

"One of the defining features of the last few months is we have officials in foreign governments saying one thing and the private sector saying another. You have officials talking tough. They're promising to resist U.S. sanctions and they're going to help the companies, and companies are saying we're not sure we want to," said Reed. India, for instance, imported a record amount of crude, about 770,000 barrels, last month through state-owned companies, even though its private-sector refineries said they were backing away from Iranian oil.

Reed said some buyers of Iranian crude have ramped up imports ahead of time and will cut back closer to the deadline, promising to reduce imports from now elevated levels, in the hope that will help reduce the impact of sanctions. Reed said the major buyers of Iran's crude will continue to be India, Turkey and China, while other Asian buyers, such as Japan and South Korea, are clearly cutting back.

"If countries are going to cut oil imports to get exemptions from the U.S. government, they'll do that in September and October, before the deadline. We could see volumes come off the market before then," Reed said. That could add to volatility in oil prices, but also by then Saudi Arabia will be exiting its own high-demand period, when it uses about 500,000 more barrels a day in the summer to generate electric power. It could send those additional barrels to the market.

Croft said Iran could restart its nuclear program as it attempts to agitate the U.S.

Croft also said it's too soon to judge the potential damage to the Iranian regime. "We might be in a different moment than we were in 2009. But the leadership doesn't show it's willing to blink at this moment," Croft said.

"The long story short, if there is a serious crisis of legitimacy underway, the regime doesn't seem to have an answer for it," said Reed. "It is an existential crisis. The protests are too small, but if you look at what officials and former officials are saying in Iran to each other, they're clearly worried the system is in trouble, maybe mortal danger. It is clearly blunt talk coming from officials," he said.

One concern among analysts is what would happen if the current regime were to be toppled. Kilduff said Rouhani may want to come to the table to talk to Trump ultimately. "The Iranians need an out. They're going to get desperate quick," he said, noting it could be a more right-wing regime that could take over.

Reed said Iran has options for now. "One of the big ones is to�threaten international shipping in the Middle East,�which they've done more explicitly over this summer," he said. "They're going to try every trick in the book. They're going to resort to some old tricks they have at times used. ... They have to wait and see what happens to the Trump administration. They have to see what happens in the midterm elections in the U.S. This is a story that's going to drag on."