Per international sanctions regulations, you are not authorised to access the PayPal system".
Prominent Swedes defied sanctions regulations by taking up a collection for their legal fees.
It is not clear how many Iranian nationals are held in the UK for crimes such as violating sanctions regulations.
Under the newly amended sanctions regulations, Americans can also purchase and consume Cuban-origin alcohol and tobacco while abroad.
ThyssenKrupp, a German steel company that has had decades of experience in Iran, said it abided by all export and sanctions regulations.
The detainees, who included Washington Post journalist Jason Rezaian, were freed as part of a prisoner swap for a number of Iranian nationals held in the US for crimes including violating sanctions regulations.
The Treasury action came only a few weeks after an Iranian tennis referee, Adel Borghei, hired in May to work at the United States Open, was blocked from taking the job because of sanctions regulations enforced by the Treasury Department.
It is still unclear why Iran is holding the Briton, but earlier this year, Iranian authorities released a group of previously detained Iranian-Americans, notably Washington Post journalist Jason Rezaian, as part of a prisoner swap with the US in exchange for a group of Iranians held in the US for crimes such as violating sanctions regulations.
"The Iranian transactions and sanctions regulations prohibit the exportation of goods, services or technology directly or indirectly from the United States or by a US person to Iran and would generally prohibit US-registered aircraft from flying to Iran," Psaki told reporters at a regular briefing.
Additionally, apps facilitating transactions for businesses or entities based in Iran may not comply with the Iranian Transactions Sanctions Regulations (31CFR Part 560) when hosted on the App Store.
