The Obama administration secretly organized an airlift of $400 million worth of cash to Iran that coincided with the January release of four Americans detained in Tehran, according to U.S. and European officials and congressional staff briefed on the operation afterward.

 

U.S. Secretary of State John Kerry speaking with Iranian officials including his counterpart, Javad Zarif

 

Wooden pallets stacked with euros, Swiss francs and other currencies were flown into Iran on an unmarked cargo plane, according to these officials. The U.S. procured the money from the central banks of the Netherlands and Switzerland, they said.

 

The $400 million was paid in foreign currency because any transaction with Iran in U.S. dollars is illegal under U.S. law. Sanctions also complicate Tehran’s access to global banks.

 

The money represented the first installment of a $1.7 billion settlement the Obama administration reached with Iran to resolve a decades-old dispute over a failed arms deal signed just before the 1979 fall of Iran’s last monarch, Shah Mohammad Reza Pahlavi.