In comments that may set up a catastrophic amount of fallout in international trade, officials from the Trump Administration say that China will absolutely not be given any time to "wind-down" their purchases of Iranian oil, nor any extensions beyond May 1. 

China is by far Iran's largest customer, and would have by far the hardest time sourcing enough replacement oil on the market. These comments are likely to have an impact on the oil market, pushing prices higher, and more importantly, risking a US ultimatum on China. 

The implication of the waiver loss is that any country that buys Iranian oil after May 1 will be cut off from the US, and by extension the world's, banking system. Doing that with China, a major US trading partner and a huge economic power, would be catastrophic to the world economy. 

US officials are dismissing this as a concern, saying they believe the huge consequences are exactly why China will ultimately cave to US demands. China, however, has long insisted they can't afford to stop buying from Iran, and under the P5+1 nuclear deal, of which they are still a party, they are under no obligation to stop.