2010-07-02 06:31

WASHINGTON?- US President Barack Obama will say on Thursday that the toughest-ever US sanctions on Iran aim to strike "at the heart" of the Islamic Republic's ability to develop and fund its nuclear programs.

Iranian President Mahmoud Ahmadinejad speaks during an anti-chemical weapon ceremony in Tehran June 29, 2010. [Agencies]?

"There should be no doubt -- the United States and the international community are determined to prevent Iran from acquiring nuclear weapons," Obama will say at the signing of the Iran Sanctions Act Thursday evening, according to remarks prepared for delivery.

He will say the new US sanctions on Iran are the toughest-ever passed by the US Congress and will make it harder for that country to buy refined petroleum as well as goods and services to modernize its oil and natural gas sector.

The sanctions go much further than the measures agreed to by the UN Security Council last month and are aimed at ratcheting up pressure on Iran to return to international talks over its disputed nuclear program.

The United States and its European allies suspect Iran is trying to build an atomic bomb under the cover of its uranium enrichment program, despite Tehran insistence that it is for the peaceful generation of electricity.

The new US sanctions penalize companies supplying Iran with gasoline and international banking institutions doing business with Iran's Islamic Revolutionary Guard Corps or its nuclear program.

Foreign banks that do business with key Iranian banks or the Revolutionary Guards will not be allowed access to the US financial system. Global suppliers of gasoline to Iran could also face bans on access to the US banking system, property transactions and foreign exchange in the United States.