Iran has moved its nuclear development program up another notch, activating a second centrifuge cascade in its race to enrich uranium.

The Islamic Republic had notified the United Nations International Atomic Energy Agency in March of its intent to link a second cascade to one that had already been brought online in February. The second set of 164 centrifuges, like the first, is located at the Natanz pilot fuel enrichment plant.

The IAEA told the Associated Press the move has enabled Iran to produce enriched uranium at up to 20 percent in the two linked cascades.

On July 17, “Iran was feeding nuclear material to the two interconnected 164-machine centrifuge cascades, contrary to U.N. Security Council resolutions affirming that Iran should suspend all enrichment related activities” when agency inspectors visited the facility, according to IAEA spokeswoman Gill Tudor.

Once enriched to 20 percent, uranium is considered weapons-grade nuclear material. At 95 percent enrichment, uranium may be used to build an atomic bomb. Although Iran denies its intent is hostile, Israeli and other Western intelligence sources believe the Islamic Republic intends to create a nuclear weapon, and Iranian President Mahmoud Ahmadinejad has repeatedly threatened in public speeches to annihilate the State of Israel.

After debating the issue for months, the U.N. Security Council finally voted in June to impose a fourth round of economic sanctions against Iran in an attempt to pressure the country to end its nuclear development program. The United States, Australia and the European Union quickly followed up with increased sanctions of their own.

Iran has responded with an announcement by Vice President Mohammad Reza Rahimi that the country will “remove the dollar and euro from our foreign exchange basket and will replace them with (the Iranian) rial and the currency of any country cooperating with us. We consider these currencies (dollar and euro) dirty and won't sell oil in dollar and euro,” Rahimi told the Fars news agency.

Over the past two years, Iran has tightened its ties with Venezuela, which possesses the largest supply of crude oil in the Western hemisphere. In addition, The Islamic Republic has also begun to tighten its diplomatic ties with Brazil, Syria and Turkey, which signed an agreement to process Iran's uranium abroad, in defiance of U.N. sanctions.