Oil prices rose on Monday as investors focused on the impact of US sanctions on Iran despite assurances by Washington that Saudi Arabia, Russia and the United States could together raise output fast enough to offset falling supplies. US Energy Secretary Rick Perry said in an interview with Reuters on Friday that he did not expect any price spikes and that the world's top three oil producers could between them raise global output in the next 18 months, reports Reuters.
Brent crude oil was up 45 cents a barrel at $78.54 by 0830 GMT. US light crude was up 45 cents at $69.44.
Iran's oil exports have been falling in recent months as more buyers, including its second-largest buyer India, cut imports ahead of US sanctions that take effect in November. Washington aims to cut Iran oil exports down to zero to force Tehran to re-negotiate a nuclear deal.
"Iranian crude oil export loadings have declined by 580,000 barrels per day in the past three months," Bank of America Merrill Lynch analysts said in a note to clients on Monday.
A leading Iranian official said on Saturday that Saudi Arabia and Russia had taken the oil market "hostage" and accused other producers of turning the Organisation of the Petroleum Exporting Countries into "a US tool".
Iran is the third-largest OPEC producer.
A deepening trade war between United States and China is unsettling commodities and energy markets.