The United States is looking at imposing fresh sanctions against Iran’s petrochemical industry, according to diplomatic sources quoted by CNN.

The new measures will bar foreign companies from dealing with Iran’s petrochemical industry under threat of being banned from U.S. markets. U.S. companies are already barred from dealing with Iran.

The new sanctions are reportedly meant to “build on existing sanctions on Iran’s oil and gas industry.”

The report follows the International Atomic Energy Agency’s announcement of its concern over possible military dimensions to Iran’s nuclear activities. Iran denies all allegations.

The European Union has also said it is looking at increasing pressure on Iran.

Russian Foreign Minister Sergey Lavrov has said, however, that imposing sanctions on Iran is not an effective approach, stressing that diplomatic talks and negotiations provide the only path toward an adequate solution.

On Friday, the IAEA Board of Governors issued a resolution on Iran, expressing growing concern over Iran’s nuclear activities and urging Iran to submit to previous UN resolutions.

Those resolutions have called on Iran to end its uranium enrichment activities, but Iran refuses to do so, insisting that the enriched uranium is only used as fuel for its nuclear reactors.