Geng said that China, which has for years been a close economic partner with Iran, will "carry on the normal and transparent pragmatic cooperation with Iran on the basis of not violating our worldwide obligation".
A senior State Department official said Wednesday that the US and Israel worked closely together leading up to US President Donald Trump's decision to quit the Iran nuclear deal and reimpose sanctions on Tehran over its nuclear program.
PARIS - France's finance minister says European countries should push back harder against the Trump administration over the Iran nuclear deal and not act as "vassals" to the U.S.
Energy analysts expect other major customers of Iran - including close U.S. allies Japan and South Korea - to adhere more closely to new sanctions.
Days after the USA president walked away from a three-year-old nuclear deal, senior administration officials said monitoring should continue regardless.
Iran is a major oil producing country. The increased demand helps to overcome the over-crowding that has been pursuing the markets.
And it came amid growing tension between the Sunni kingdom and the Shiite Islamic republic over Iran's support for the Huthi rebels in Yemen, who have been firing rockets across the border.
"We do not want to let Iran use the United States financial markets and financial system and transact in dollars until they agree that not only will they not have a nuclear weapon now, but we've put in provisions that they will never have one", Mnuchin said.
Iran's crude oil exports surged by 1 million barrels per day after the nuclear deal took effect in early 2016. BofA doesn't expect Iran's crude oil exports to change much in the coming months.
Tourism in Iran had also benefited from the nuclear deal, with visitor numbers increasing from 3.8 million visitors in 2012 to over 5 million in 2015, and this could also be affected by renewed sanctions.
Saudi Arabia also backed Trump's decision on his country withdrawing from the Iran nuclear deal.
They would have to wind up investments by November or face U.S. sanctions. For oil and other petroleum products there will be a 180-day period in which people doing business with Iran will be able to wind down those operations before facing penalties.