“In the coming weeks we will continue to increase the financial pressure on Iran,” Geithner said. “We will continue to target Iran’s support for terrorist organizations.”

Shipping, insurance and energy firms targeted by sanctions

The sanctions forbid financial transactions between Americans and the designated entities and also freeze any assets they may have in U.S. jurisdictions.

Among the other new US targets are five front companies and a list of more than 90 names of ships that Iran’s national maritime carrier has been using to try to evade sanctions.

The United States also added to its sanctions list 22 petroleum, energy and insurance companies located inside and outside Iran that are owned or controlled by the Iranian government, Levey said. Of those, eight are based in Britain, with headquarters in London; six are based in Iran; three are based offshore in Jersey, two each in Singapore and the United Arab Emirates, and one in Germany.

European Union approves new sanctons

The European Union also adopted a new set of sanctions against Iran on Thursday.

The restrictions were approved during a summit focused primarily on economic issues, spokeswoman Maja Kocijancic said.

A statement said the sanctions target dual-use items that could be used as part of a nuclear program, and Iran’s oil and gas industry — including the “prohibition of new investment, technical assistance and transfers of technologies.”

Iran’s shipping and air cargo companies will be banned from operating in EU territory, and new visa bans and asset freezes will be imposed on Iran’s Revolutionary Guard. The sanctions also encompass trade insurance and financial transactions.

Ahmadinejad defiant

Earlier Wednesday, before the US announcement was made, Tehran said it would expand its atomic research by building four new reactors.

President Mahmoud Ahmadinejad pledged to punish the West and force it to “sit at the negotiating table like a polite child” before agreeing to further talks. He said Iran will not make “one iota of concessions,” adding that he would punish world powers for the UN sanctions before announcing new conditions for negotiations.

“You showed bad temper, reneged on your promise and again resorted to devilish manners,” he said in speech broadcast live on state TV.

The UN Security Council now has passed four sets of international sanctions against Iran.