The English-language Press TV in Tehran reported Wednesday that Iran had ceased exports to Greece, France, Portugal, Spain, Italy and the Netherlands, The Jerusalem Post reported.
The European Union, a 27-nation political region, has agreed to join in sanctions against Iran that are to start July 1.
Iranian Oil Minister Rostam Qasemi said this month that Iran would cut exports to "some European countries." He also said, "We will decide about other European countries later."
U.S. President Barack Obama has led the intentional effort to sanction Iran, signing a law last year to prohibit transactions with Iran's central bank, which is how most oil payments are made to Iran.
The price of Brent crude oil, the pricing standard in Europe, gained $1 to $118.35 after Iran's export ban was made public.