Press TV - The United States has announced reimposition of the �toughest� sanctions ever against Iran in an attempt to curtail the Islamic Republic�s oil exports and put extra pressure on the country's economy.

US Secretary of State Mike Pompeo and Treasury Secretary Steven Mnuchin took the podium at the State Department�s Foreign Press Center in Washington on Monday to unveil what the White House claims will force Iran to abandon its nuclear and ballistic missile programs while rolling back Tehran�s influence in the Middle East region.

Pompeo said the US had successfully persuaded over 20 countries to stop or dramatically reduce their oil imports from Iran, causing Tehran�s overall sales to suffer by more than 1 million barrels per day.

The campaign of pressure had also taken away over $2.5 billion in Iran�s oil revenue, he further claimed.

However, the top US diplomat admitted that Washington had failed to get the main buyers of Iranian oil to tag along and had to grant temporary waivers to China, India, South Korea, Turkey, Italy, Greece, Japan and Taiwan.

On Friday, the US administration agreed to allow the eight countries to continue purchasing Iran�s crude oil after Washington�s sanctions on Tehran take place.

A�US administration official told Bloomberg�that waivers were aimed at preventing oil price hikes and would be granted in exchange for continued import cuts.

The new round of US sanctions also target Iran's nuclear activities, which the US insists are in breach of the 2015 nuclear deal between Iran and six world powers.

The US allegations against Iran's nuclear program come�as Yukiya Amano, the head of the International Atomic Energy Agency (IAEA), has in numerous reports verified Iran's commitment to the nuclear deal since its implementation.

Pompeo said Washington had authorized three waivers for �nonproliferation projects� that Iran was pursuing as part of its nuclear program, although they will be �very narrow, very limited and very time-limited.�

Alleging that Iran was a �destabilizing force� in the region, Pompeo said the US would continue to put more pressure on Iran until Tehran fulfills the 12 demands that he outlined at the Heritage Foundation in Washington, D.C., back in May.

The 12 infamous demands included, among other things, shutting down all uranium enrichment facilities, granting unrestricted access to inspectors from the UN nuclear body, releasing all US citizens kept in Iran and ending military advisory roles in Iraq and Syria while dropping support for Yemen�s Houthi Ansarullah movement which is fighting a years-long Saudi Arabian military aggression.

Earlier on Monday, Iranian Foreign Ministry's spokesman, Bahram Qassemi said implementation of the new US sanctions was another sign of America's isolation.

"These sanctions mark the advent of further American isolation..., since they are applied by America only and not by the (United Nations) Security Council and the entire world," the spokesman said, adding,�"America's dreams are nothing that would come true, and these measures (the sanctions) are indicative of the US officials' inadequate knowledge of regional and global matters.

Mnuchin also addressed reporters on Monday, noting that the US Treasury�s �largest ever single-day action� against Iran covers 50 Iranian banks and subsidiaries, more than 200 persons and vessels in its shipping sector, and the country�s national airline, Iran Air, and more than 65 of its aircraft.

According to Mnuchin, new sanctions also put nearly 250 persons and associated blocked property on the list of Specially Designated Nationals and Blocked Persons (SDN List).

He added that Treasury's imposition of unprecedented financial pressure on Iran was aimed to make the Iranian government "face mounting financial isolation and economic stagnation."

The Treasury secretary�s remarks echoed almost word for word what US President Donald Trump�said back in May, when he pulled Washington�out of the nuclear deal-- known as the Joint Comprehensive Plan of Action (JCPOA) -- while pledging to intensify his actions against Iran.

Stressing that his country will be �relentless� in pressuring Iran, Pompeo also said the sanctions were going to accelerate what he called the �rapid decline of Iran�s international economic activity.�

Earlier on Monday, Iranian President Hassan Rouhani downplayed the effect that Washington�s actions might have on Iran�s economy, saying that Tehran will break the sanctions.

"With the help of the people, and the unity that exists in our society, we have to make the Americans understand that they must not use the language of force, pressure, and threats to speak to the great Iranian nation. They must be punished once and for all," the Iranian president said.

Speaking in�an exclusive interview over the weekend with USA TODAY, Iran's�Foreign Minister Mohammad Javad Zarif said�Washington forces the international community to break a nuclear deal that was enshrined in United Nations Security Council resolution 2231, adding that new sanctions were nothing out of the ordinary for the Iranian people.

"Iran is used to US sanctions. We've had them for almost 39 years," Iran's top diplomat added.