Iran has threatened to block the flow of oil through the Strait of Hormuz if Western governments attempt to impose sanctions on its petroleum exports in their dispute over its nuclear ambitions.

The official Iranian news agency IRNA quoted Vice President Mohammad Reza Rahimi as saying that if Iranian oil is banned “then not a drop of oil will pass through the Strait of Hormuz.”

Rahimi was quoted as saying Iran does not want hostilities but that Westerners are not willing to give up “their plots.”

The blunt warning came as Iran's naval forces continued a 10-day exercise in the Strait and nearby waters that began Saturday.

In Washington, U.S. State Department spokesman Mark Toner dismissed the threat as “bluster.” He called the comments “another attempt to distract attention from [Iran's] continued noncompliance with international nuclear obligations.”

Iran contends its uranium enrichment program is for civilian purposes, but a United Nations report issued last month said Tehran appears to be secretly working on designing an atomic weapon and missile delivery system.

European Union ministers have said that a decision on further economic sanctions – including the question of whether to boycott Iranian oil – would be made in the coming weeks. The vast majority of Iran's foreign revenue comes from oil exports.

More than one-third of the world's tanker-borne oil supply passes through the Strait of Hormuz.