TEHRAN, Iran (AP) — The cargo of four tankers seized by the United States last week en route to Venezuela was no longer Iranian property, Iran's oil minister said Monday, insisting that the U.S. had no right to confiscate the shipment in international waters.

The Trump administration said it seized the cargo of four tankers it was targeting for transporting Iranian fuel to Venezuela. The move was part of stepped-up U.S. campaign of maximum pressure on Iran and Venezuela, both heavily sanctioned allies.

According to the semi-official ISNA news agency, Oil Minister Bijan Namdar Zanganeh said the oil had been “sold to customers and the payment was received" for it.

“The U.S. claimed it seized Iranian petrol, but even though the cargo was sent from Iran, neither the ships nor the petrol were Iranian,” Zanganeh was quoted as saying.

He did not elaborate or say who the owners of the petrol was at the time of the seizure. But Zanganeh's remarks echoed those of Iranian Foreign Minister Mohammad Javad Zarif who on Sunday called the U.S. “pirates of Caribbean” in a tweet and said the ships carried sold cargo. Iran's ambassador to Venezuela, Hojad Soltani, also said that neither the ships not the oil were Iranian.

“Sadly for them, stolen booty wasn’t Iran’s. Fuel was sold F.O.B. Persian Gulf. Ship and flag weren’t ours either,” Zarif tweeted.

Iranian officials have called pushed for stronger ties between Iran and Venezuela, and Tehran has sent several fuel shipments to energy-hungry Venezuela amid U.S. sanctions.