The United States is reportedly preparing to hit Iran with additional sanctions following a report that Iran appeared to be working on designing an atomic bomb and may be carrying out related testing and research.

Sources told Reuters Friday the U.S. plans to sanction Iran’s petrochemical industry and is likely to get other countries on board as well.

Reuters reported:

The sources, who said the sanctions could be unveiled as early as Monday, said the Washington wanted to find a way to bar foreign companies from aiding Iran’s petrochemical industry with the threat of depriving them access to the U.S. market.

While European nations typically resent “extra-territorial” U.S. sanctions on their companies, the sources, who spoke on condition of anonymity, said in this case the Europeans would likely follow suit, though not immediately.

White House press secretary Jay Carney had previously said the U.S. would be increasing pressure on Iran to cease its nuclear weapon ambitions, though did not provide details. The White House has not commented on the latest sanction reports.

On Saturday, the brother of an Iranian Revolutionary Guard commander killed during an explosion at a weapons depot last week told state media the commander had been testing an intercontinental missile.

The U.S. approved sanctions last year that targeted Iran’s energy and banking sectors, and now going after the country’s financial sector appears to be a possibility, according to Reuters:

The sources said there had also been discussion of sanctions on the Iranian financial sector, possibly by limiting certain transactions through the Iranian central bank, but not through a blanket effort to cut it off entirely.

While U.S. officials last week said the idea of cutting off the Iranian central bank entirely was off the table for now, several sources said there had been consideration of more limited measures.

Israel has ramped up talk in recent weeks about a possible strike against Iran’s nuclear weapons program, with Israeli Defense Minister Ehud Barak saying they would not “take any option off the table.”

Secretary of Defense Leon Panetta planned to warn Barak on Friday that a military strike against Iran’s nuclear infrastructure could have serious economic consequences, Fox News reported.

But according to Fox, Joint Chiefs Chairman Gen. Martin Dempsey said a military option is not out of the question.

“I don’t choose to talk about our discussions with our Israeli partners, but I will tell you we are on a dual-track approach, economic and diplomatic, with never taking the military option off the table. And I think that’s the right place to be,” Dempsey said.