(CNN) -- The United States slapped new sanctions on Iran on Thursday, targeting a handful of companies and individuals it says are providing materials and technology to Tehran's nuclear program.
The sanctions announced Thursday by the U.S. State and Treasury departments came the same day U.N. nuclear watchdog inspectors wrapped up one-day talks in Iran over its nuclear program, widely suspected by the United States and other Western nations as a front for the country's development of nuclear weapons -- a charge Iran has repeatedly denied.
The talks between Iran and the International Atomic Energy Agency were aimed at jump-starting negotiations, while allowing agency inspectors to gain access to a military complex where Tehran is suspected of testing nuclear materials.
The IAEA did not immediately detail the talks or whether its inspectors would be granted access to the Parchin military complex, outside of Tehran.
Western sanctions hamper Iran's economy
How sanctions hurt Iran
Reality Check: Nuclear Iran
The sanctions -- the latest in a series to target Iran's economy as well as its ability to develop nuclear material -- were essential "given Iran's continued intransigence on its nuclear program," said Victoria Nuland, the U.S. State Department spokeswoman.
There was no immediate reaction from Iran's government over the latest sanctions.
Among the targets of the latest sanctions is Prof. Fereydoun Abbasi Davani, the head of the Iran Atomic Energy Organization.
Abbasi Davani and his wife survived a car bomb two years ago that Tehran has blamed on Israel. At least four scientists associated with Iran's nuclear program have been killed since 2010.
The companies being targeted with sanctions: FaraTech, the Neda Industrial Group, Aria Nikan Marine Industry, Towled Abzar Boreshi, Iran Pouya, Terjerat Gostar and Tarh O Palayesh.
The sanctions freeze the companies' assets and prohibit business dealings in or with the United States. Companies and banks that defy the U.S. sanctions could be cut off from the U.S. financial system, the State and Treasury departments said.
Iran maintains its nuclear program is for civilian energy purposes only. But the IAEA has said it cannot verify whether the intent of the program is for peaceful means.
A number of Western nations have placed economic and arms-related sanctions on Iran since November 2010 when the IAEA said Tehran was pursuing technology that could be used to build nuclear weapons.
Since then, Iran has been hit by the United States and the European Union with an oil embargo as well as sanctions targeting its banks and number of its businesses.