BRUSSELS — The European Union toughened sanctions against Iran on Monday because of the disputed Iranian nuclear program, banning trade in sectors such as finance, metals, and natural gas and making business transactions in many other areas far more cumbersome.
The European Union’s foreign ministers agreed to the measures, the most far-reaching since it slapped a ban on oil imports in July, at a regular meeting in Luxembourg.
In a joint statement, the ministers expressed ‘‘serious and deepening concerns over Iran’s nuclear program’’ and said Iran ‘‘is acting in flagrant violation of its international obligations.’’
The decision comes amid growing evidence that sanctions aimed at forcing Iran to suspend its uranium enrichment activities have begun to inflict serious damage to its economy.
“We want to see a negotiated agreement’’ with Iran, Catherine Ashton, the Union’s foreign policy chief who represents six major powers including the United States, said ahead of the meeting. ‘‘But we will continue to keep up the pressure,’’ she said, adding that the sanctions policy ‘‘is important because it’s quite clearly having an effect.’’
Ashton said talks were set to continue with Saeed Jalili, Iran’s nuclear negotiator, in order to assess when to convene another meeting. She has held five rounds of talks with Iranian negotiators since late 2010.
Iran is suffering acute inflation from the weakness of the rial, the national currency, which lost 40 percent of its value against the dollar this month. Outside economists have pointed to Iran’s currency troubles as evidence that the sanctions, which have severely restricted Iran’s ability to sell oil and do international banking transactions, are having a profound impact.
New signs of problems were reported Friday, with severe drops in Iran’s monthly oil production, automotive production, and the number of foreign commercial ships docking in Iranian ports.
The sanctions were necessary as a result of a ‘‘continued failure to satisfy the world that the [nuclear] program was for peaceful purposes,’’ said William Hague, the British foreign secretary.
But Carl Bildt, the Swedish foreign minister, emphasized the need for a more intensive diplomatic effort alongside sanctions. “I think there are voices that sound like they want a war,’’ Bildt said. ‘‘We don’t want war.’’
A diplomatic solution continues to be ‘‘under discussion, although not always necessarily in the public domain,’’ he said.
Iran has insisted that the sanctions will have no effect on the country’s uranium enrichment program, which the Iranians have called peaceful and legal but the West has called a guise for the development of nuclear weapons capability.
The EU ministers also warned that they would take further diplomatic and economic steps if the government in Tehran failed to quell concerns over its nuclear program.
While traveling in Baku, Azerbaijan, Iran’s foreign minister, Ali Akbar Salehi, said the sanctions would have no lasting effect on the Iranian economy.