The EU sanctions would complement UN sanctions already imposed to convince Iran to abide by UN Security Council resolutions ordering it to stop uranium enrichment.
Brown announced on June 16 that Britain will freeze the assets of Iran's largest bank, Bank Melli, and that the European Union would target Iran's oil and natural-gas sectors.
"If Iran continues to ignore United [Nations] resolutions, to ignore our offers of partnership, we have no choice but to intensify sanctions. And so today Britain will urge Europe and Europe will agree to take further sanctions against Iran," a confident-sounding Brown said at a London news conference with visiting U.S. President George W. Bush.
"First of all, we will take action today that will freeze the overseas assets of the biggest bank in Iran, the Bank Melli, and second, action will start today for a new phase of sanctions on oil and gas," he added.
The problem is, the other member states don't seem to know exactly what Brown means.
Cristina Gallach, the spokeswoman for EU foreign-policy chief Javier Solana, said the question of sanctions against Iran was not even discussed at the June 16 foreign ministers' meeting in Luxembourg, the meeting Brown was referring to.
Gallach acknowledged, however, that the EU states are "ready to move further" on Iran. So, it's probable Brown's announcement is just a little ahead of actual events.
Moves to sanction Iran's energy resources could be a highly effective tool, because Iran must import much of its refined oil products due to a lack of its own refining capacity. And gas exports are a major source of revenue for the stumbling Iranian economy.
As for Bank Melli, Brown said Britain would act the same day to freeze its overseas assets. The move may come too late to be fully effective, as Melli is reported by some European and Iranian media to have withdrawn billions of dollars from its British accounts, in expectation of a freeze.
Brown's tough comments come after Solana flew to Tehran on June 14-15 to present the Iranian leadership with a new and upgraded incentives package to persuade it to abandon uranium enrichment.
The package of economic, technological, and political incentives has been drawn up by the five permanent members of the UN Security Council and Germany. It is the latest version of incentives that have been offered repeatedly and unsuccessfully to Tehran for years.
Iranian government spokesman Gholamhussein Elham has already said Iran will not accept the latest package if it demands the suspension of uranium enrichment -- which it does.
Nevertheless, Solana and the Europeans are determined to wait for a formal response from Iran before going forward with sanctions.
But behind the scenes, the mood among those who have backed the incentives path is said to be changing. AP quoted an EU diplomat as saying the apparent failure of Solana's trip to Tehran is a turning point that has accelerated Europe's drive to tighten sanctions.
with additional agency reporting