The $1.7 billion cash payment that the White House recently sent to Iran suggests that Washington may have transferred to Tehran more than $33 billion in untraceable cash and precious metals since 2014, giving the Islamic Republic greater flexibility to launder money and finance terrorism.

After the Obama administration transferred $400 million in cash to Iran, raising numerous questions relating to its purpose and whether it was a ransom payment for detained American hostages, House Republicans vowed to work to prevent another such ransom payment in the future.

A $1.7 billion payment by the US to Iran that coincided with the release of American hostages in January is helping Tehran boost its military budget by 90% in the next year. Some US lawmakers are concerned that the money was in fact a ransom payment by the Obama administration.