Iran has stopped oil exports to British and French companies, the Islamic republic's oil ministry said on Sunday.
A statement the ministry's website that Iran, OPEC's second biggest oil producer after Saudi Arabia, would sell oil to "new customers."
Iran's English-language television station Press TV said the move was "in line with the decision to end crude exports to six European states."
The European Union said last month it would stop importing Iranian crude from July 1 in a bid to force Iran to agree to halt its nuclear program. Western powers suspect Iran of seeking to create a nuclear bomb but Tehran insists its program is peaceful.
Iranian media reported on Wednesday that Iran had cut oil exports to the Netherlands, Greece, France, Portugal, Spain and Italy in response to the EU oil embargo, but the country's oil ministry later denied this.
The 27-nation bloc currently buys about 20 percent of Iran's oil exports.