Trump said he would reintroduce sanctions and Washington later told countries they must stop buying Iran's oil from November 4 or face financial consequences.
In an interview with state television, Iranian oil minister Bijan Zanganeh said: "Mr Trump sends every day a new message that creates uncertainty in the market".
Perhaps no one told him that Iran was a founding member of OPEC?
He further said the anti-Iran efforts by the USA president were largely to blame for the high oil prices in worldwide markets.
"We are working to minimize disruptions to the global market, but we are confident that there is sufficient global spare oil production capacity", Brian Hook, the director of policy planning, said on July 2.
Libya's national oil production fell to 527,000 barrels per day from a high of 1.28 million bpd in February following recent oil port closures, the head of the National Oil Corporation said in a statement on Monday.
However, Opec and its allies are doing what they can to offset crude output shortfalls that have kept global supplies tight and prices high, but they don't want to overdo it, according to UAE Minister of Energy and Industry Suhail bin Mohammed Faraj Faris Al Mazrouei.More news: 76ers say LeBron James 'strongly' considered Philly
"There hasn't been a significant change in our production and exports so far, and in response to US actions Iran will advance according to its plans and policies", Zanganeh said. "Some of the companies are trying to find other options other than Iran, be it the kingdom (Saudi Arabia), Emirates, Iraq or Kuwait", he said.
The United States in May said it was walking away from the 2015 nuclear deal between Tehran and world powers.
After India-US relations soured over India's oil imports from Iran, Iran has put India in a spot of bother now.
Iran, OPEC's third-largest producer, is facing USA sanctions on its oil exports that are prompting some buyers to cut purchases. "Full utilization would be sufficient to keep the markets well-supplied and prices in check", the analysts said.
"There will remain no such organization (as OPEC) in the future after continuation of the sanctions" against Iran, he was quoted as saying.
South Korean buyers of Iranian crude and condensate are SK Energy and SK Incheon Petrochemical, owned by SK Innovation, Hyundai Oilbank Corp and Hanwha Total Petrochemical Co.