The restoration of sanctions is part of a wider effort by U.S. President Donald Trump to force Iran to curb its nuclear and missile programs as well as its support for proxy forces in Yemen, Syria, Lebanon and other parts of the Middle East.
Earlier Monday, Israeli Defence Minister Avigdor Lieberman called the new sanctions a "critical" blow to Iran's actions in the region.
The US sanctions herald the end of Washington's involvement in the landmark 2015 deal signed between Iran, the US and other world powers, which was created to curb Iran's nuclear ambitions.
In particular the sanctions target Iran's vital energy sector and its shipping and shipbuilding sector and banking sector.
This time, however, the US sanctions are stoking up global tensions to a more severe degree.
Saudi Arabia is the only country with the capacity to make up for lost Iranian oil production. Oil is the country's top export.
After pulling the USA out of the deal struck between Iran and six major powers - Britain, China, France, Germany, Russia and the United States - the administration began reimposing sanctions on the Islamic Republic in August.
The United States again restricted Iran's oil and financial industry on Monday. "We expect to see more progress as our sanctions start to bite". Among those are the biggest buyers of Iran's oil, China and India, as well as other key United States allies - Japan, South Korea, Turkey, Italy, Greece, and Taiwan. Eight waivers to the ban on Iranian oil imports were issued to China, India, Italy, Greece, Japan, South Korea, Taiwan and Turkey.
He said Washington believed the Iranian nation had lost their confidence in its clerical rulers.
On Monday, the U.S. restored sanctions targeting Iran's oil, banking and transport sectors and threatened more action to stop what Washington calls its "outlaw" policies, steps Tehran calls economic warfare and vowed to defy.
"The US allies are seeking to oppose the US unilateralism to show their economic independence from US politics".
As NPR's Colin Dwyer reported recently, "Since May, when President Trump vowed to unilaterally pull the US out of the Joint Comprehensive Plan of Action, his administration has telegraphed its intentions to restore the sanctions that had been lifted as part of the pact".
China is a signatory to the 2015 Joint Comprehensive Plan of Action - which includes Britain, France, Germany and Russian Federation - that Trump pulled out from earlier this year.
The US stance has already inflicted serious pain on Iranians, with the country's currency, the rial, losing more than two thirds of its value since May.
Although imports of oil were temporarily allowed under the waiver, Korea still can not trade with Iran in any other business area such as automobiles, finance, shipbuilding, energy or minerals.
Oil markets have been anticipating the sanctions for months and the world's biggest producers have been increasing output.
Dubowitz added, "They don't want all the Iranian oil off the market November 5, because that would spike the price and send additional revenues to Iran".
U.S. West Texas Intermediate (WTI) crude futures CLc1 were at $62.86 a barrel at 0800 GMT, down 24 cents, or 0.4 percent, from their last settlement.
Separately, national security adviser John Bolton said: "These are not permanent waivers, no way". "Today, Iran is able to sell its oil and it will sell", President of Iran Hassan Rouhani said.
The curbs come as the United States is focused on U.S. congressional and gubernatorial elections on Tuesday.
Japan said on Tuesday that it would soon raise imports from Iran in accordance with the waivers.