Gibraltar authorities on Sunday rejected the United States' renewed request of not releasing Iranian oil tanker Grace 1, citing the inability to comply with it due to European Laws.
"The Central Authority's inability to seek the Orders requested is a result of the operation of European Union law and the differences in the sanctions regimes applicable to Iran in the EU and the US", Sputnik news agency quoted a statement by Gibraltar government.
"The EU sanctions regime against Iran - which is applicable in Gibraltar - is much narrower than that applicable in the US", it added.
Following Thursday's decision by the Gibraltar Supreme Court to end the detention of Grace 1, the US had issued a warrant for the seizure of the tanker on the grounds that it had links to Iran's Islamic Revolutionary Guard Corps (IRGC), which Washington has designated a "terrorist" organisation.
The oil tanker was seized off the shore of Gibraltar by British Royal Marines last month on the suspicion that it was exporting crude oil to Syria, thereby violating the EU sanctions.
The maritime episodes had led to an international uproar at a time when the US and Iran were already at loggerheads owing to the former's decision to withdraw from the 2015 nuclear deal.