Officials say competition between the countries is healthy. But tensions are mounting over energy quotas, regional conflicts and their different visions for the Middle East.
China told its independent refineries to disregard U.S. sanctions over their purchases of Iranian crude.
The drone and missile attacks were the first of their kind since the U.S.-Iranian cease-fire began last month. They coincided with reported clashes between American and Iranian vessels in the Strait of Hormuz.
The details of the latest plan were unclear, and President Trump did not specify his objections.
American producers are under pressure from investors to keep spending in check, and they are wary of drilling more wells because they are not sure oil prices will stay high.
Ayatollah Mojtaba Khamenei said in a statement that Iran would establish “new legal frameworks” for the Strait of Hormuz. He also said his country would retain its nuclear capabilities.
The exit of the United Arab Emirates is the most significant in a series of departures from the oil cartel in recent years.
The measures aim to crack down on Iran’s shadow banking system and Chinese purchases of Iranian oil.
The United Arab Emirates’ decision to leave OPEC has rocked the region, underscoring how the country, at odds with Saudi Arabia, is increasingly charting its own course.
The Gulf government has long complained about the group’s quotas, which officials believe unfairly limited its exports. Its departure is expected to weaken OPEC’s influence.