Monday, US sanctions will kick in, banning the purchase of US dollars, gold and other precious metals, and in early November oil, shipping and ports will be hit by the second phase of the same sanctions.
She told CNBC with regards to the USA sanctions against Iran kicking in next week, "we're looking at tougher rhetoric and potentially tougher actions over August and September".
It has warned countries which ignore the policy will face U.S. sanction, even if they are American allies.
Chinese and Indian companies "will be subject to the same sanctions that everybody else's are if they engage in those sectors of the economy that are sanctionable", a State Department official told reporters in June. "China will continue to cooperate with Iran adhering to its global obligations", she added.
USA nonfarm payrolls rose in July, but the U.S. trade deficit recorded its biggest increase in more than one-and-a-half years in June as the boost to exports from soybean shipments faded and higher oil prices lifted the import bill.
Francis Fannon, U.S. assistant secretary of state for the Bureau of Energy Resources, was recently in China to discuss sanctions, Bloomberg said, citing a U.S. government official.
The Organization of Petroleum Exporting Countries, led by Saudi Arabia, has pledged to fill any supply gaps in the market after Trump's complaints.
Like the US, Saudi Arabia is anxious about Iran's nuclear programme and accuses the country of supporting terrorists across the Middle East. United Nations inspectors said Iran was complying with the deal, but Trump felt the agreement did not go far enough.
The twin-prop planes are jointly manufactured by France's Airbus and Italy's Leonardo, but because just over 10 percent of their parts are made in the U.S., they are subject to the renewed sanctions. He has called for a new accord that would include a radical transformation of Iran's policies, including its military support for the Syrian government and regional militant groups, two issues not covered by the 2015 deal.