The European Union says talks are under way on whether a barter mechanism aimed at salvaging some trade with Iran might include oil, as Europeans scramble to ease tensions between Iran and the United States.

Following a meeting among European foreign ministers in Brussels, EU foreign policy chief Federica Mogherini said the special barter mechanism with Iran known as INSTEX would be open to third-party countries. The mechanism is aimed at working around U.S. sanctions, and for now, it narrowly targets humanitarian goods.

"The issue of whether INSTEX will deal with oil or not is a discussion that is ongoing among the shareholders," Mogherini said. "We have around 10 member states and some are considering actively dong that."

Europeans are increasingly alarmed the four-year-old Iran nuclear deal, known in shorthand as JCPOA, is on the verge of collapse — a message delivered by France, Britain and Germany as they urged nations to resume talks.

Earlier Monday, British Foreign Secretary Jeremy Hunt offered a sliver of hope.

"Iran is still a good year away from developing a nuclear bomb," he said. "There is still some closing, but small window to keep the deal alive."

French Foreign Minister Jean-Yves Le Drian said the Europeans must remain united. He criticized Iran's decision on breaching the deal's uranium enrichment caps as a bad response to a bad decision by the U.S. in pulling out last year.

Iran says the Europeans haven't done enough to compensate for the tough sanctions Washington has since reimposed against Tehran. Experts are skeptical INSTEX will have much of an impact. Mogherini acknowledged the mechanism proved much more complex than the Europeans originally expected, but she had a message for Iran.

"We're doing our best," she said, "and we hope that this will be enough for the Iranian public opinion and Iranian authorities to realize that we are committed to the full implementation of the JCPOA."

She said for now, the parties in the nuclear deal do not see Iran's breaches as significant non-compliance, noting all of Tehran's steps are reversible. Iran has long said its nuclear program is solely for peaceful purposes.

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