President Trump expressed his displeasure in a Monday tweet about OPEC's emerging plans to dial back oil production in the coming months, perhaps by a million barrels per day, although the group's meeting in Abu Dhabi did not produce a firm plan.

"Hopefully, Saudi Arabia and OPEC will not be cutting oil production. Oil prices should be much lower based on supply!"

Why it matters: Trump's tweet puts him at odds with potential moves by Saudi Arabia, which is OPEC's dominant producer, and the wider cartel as the administration is ratcheting down Iranian exports with sanctions but wants to avoid rising prices.