In an open letter to Donald Trump on Wednesday, 51 former U.S. officials and Iran experts called on the President of the United States to increase pressure on Iran.

"Now is the time to double down on the maximum pressure campaign to force the mullahs to spend their money on the Iranian people, not their nuclear ambitions, imperialism, and internal oppression," the signatories of the open letter said, in view of "reports that Tehran continues to plot attacks targeting U.S. forces".

While the maximum pressure campaign has seriously weakened the Islamic Republic’s ability to "generate revenue to support its malign activities", Iran is still able to draw on billions of stashed-away oil dollars to fund humanitarian imports, the letter said adding that Supreme Leader Ali Khamenei has billions of dollars of money "stolen from the Iranian people" in his business empire that he can use on such activities.

Radio Farda interviewed Mark Dubowitz the CEO of the Foundation for Defense of Democracies. Here are the main highlights.

Radio Farda: What is the reason for the release of the letter in which you and former U.S. government officials call on the administration not to lift any of the sanctions?

Mark Dubowitz: There's no indication that the Trump administration is going to relieve the pressure but the regime in Iran led by Foreign Minister Javad Zarif has been running an international propaganda campaign to pressure the United States to lift sanctions as a result of the COVID-19 crisis inside Iran. And the letter just reinforces a view of over 50 former U.S. government officials and Iran experts, that this is not time to relax the pressure. And that regime in Iran has hundreds of billions of dollars available to it to both provide economic support to Iranians and health support as well during this, this pandemic.

Radio Farda: The Trump administration has been always ready to help Iran with humanitarian aid so why do you believe​ that sanctions should be even harsher?

Mark Dubowitz: Well, U.S. sanctions have always exempted humanitarian trade with Iran and humanitarian trade continues to occur with, with Europe with China with other countries around the world. So as Iranian officials themselves have admitted, they've had no problem accessing billions of dollars worth of food and pharmaceuticals, and other humanitarian products. So this is essential to keep humanitarian goods flowing into Iran, but at the same time, pressure the regime, which itself is using billions of dollars to fund terrorism and support Bashar Al Assad, its nuclear and ballistic missile programs instead of spending the regimes money on helping the Iranian people.

Radio Farda: Human Rights Watch recently claimed that U.S. sanctions are having a negative effect on Iran's ability to respond to the coronovrius pandemic. What is your opinion about this statement?

Mark Dubowitz: Well, it's clear that it was a deeply flawed report based just on anecdotal evidence. If you look at the actual trade data, you see that there's been no decrease in exports of humanitarian goods from Europe, from Asia to Iran, and indeed, even the central bank governor admitted just a couple of weeks ago, in a story that Radio Farda reported that Iran had accessed over $15 billion in essential goods and humanitarian goods in the past year. The health officials and others have said that Iran has no problem accessing the ventilators and personal protection equipment and masks that are essential for treatment of protection of Iranian extremists crisis. So this is a misinformation campaign that has been run by Iran and supported by NGOs and others in and outside of Iran.

Radio Farda: Have the U.S. sanctions impeded the IRGC's ability to be active across the middle east?

Mark Dubowitz: There's certainly a lot of evidence that the IRGC and their proxies in Lebanon, Yemen, Iraq and Syria are having a significant budgetary crisis, that they are not being able to access the funds that they once did. Because the regime in Iran no longer has the hundreds of billions of dollars at its disposal that it once did as a result of the Iran nuclear deal. So the the regime and the IRGC are having to make painful budgetary choices about where to spend their money and their results. Their proxies are not receiving the kind of funding that they have in the past. So this is obviously squeezing their budgets making it more difficult to run their destructive activities. And as the sanctions become even more intense, the regime will find itself in a more difficult financial position than it has.