The Iranian oil ministry has denied that it is stopping oil exports to six European states in retaliation for EU sanctions imposed on the Islamic state's key export, shortly after the claims were made by the country's English-language Press TV.

"We deny this report … If such a decision is made, it will be announced by Iran's supreme national security council," a spokesman for the ministry told Reuters.

However, in reporting the halt to exports, Press TV had named the countries as the Netherlands, Greece, France, Portugal, Spain and Italy.

Brent crude oil prices were up $1 a barrel to $118.35 shortly after the announcement.

The Associated Press quoted Iran's semi-official Mehr news agency as saying the ambassadors of those European countries had been called to a meeting with Iranian officials to discuss the EU sanctions against Tehran over its nuclear programme.

The EU's 27 member states have decided to stop importing crude from Iran from 1 July over its disputed nuclear programme, which the west says is aimed at building bombs. Iran denies this.

Iran's oil minister said on 4 February that the Islamic state would certainly cut its oil exports to "some" European countries.