Rouhani warns over US push against buying Iran oil

Iranian President Hassan Rouhani is warning that regional oil supply could be jeopardised if the US manages to get its allies to stop buying Tehran's oil.

Rouhani spoke to Iranian expatriates in Switzerland during his visit there on Monday, with the president vowing action if the US curbs or cuts Iranian oil exports.

Rouhani didn't elaborate on the comments, but when pressured in the past Iran has threatened to close the strategic Strait of Hormuz though which one third of the world's oil supply passes.

Iran is OPEC's second-largest crude exporter with more than two million barrels a day.

After the US pulled out of the nuclear deal with Iran, Washington has been pushing allies to cut oil imports from Iran altogether by November.

The US State Department said on Monday that it remains determined to force Iran to change its behaviour by cutting its oil exports "to zero".

Brian Hook, the senior official leading negotiations with US allies on a new Iran strategy, said Washington is confident the world has enough spare oil capacity to replace Iranian crude.

And he confirmed that US secondary sanctions on firms dealing with Iran would "snap back" on 6 August for trade in cars and metals and on 4 November for oil and banking transactions.

The US ultimatum has also contributed to upward pressure on world oil prices, although Trump believes he has persuaded Saudi Arabia to offset this by ramping up its own production.