The U.S Department of the Treasury on Monday announced a 30-day extension of a sanctions waiver that allows countries to purchase Russian seaborne oil, as the conflict in the Middle East continues to roil energy markets.

The Trump administration let a Russian oil sales waiver expire, then reversed course days later. Here's why crypto traders are watching the May 16 deadline.

The waiver, which allowed purchases of Russian oil stranded at sea, has expired as of 12:01 a.m. Eastern Daylight Time on May 16.

The waiver expired one day after Sens. Jeanne Shaheen (D-NH) and Elizabeth Warren (D-MA) said it was helping Russia generate oil revenue

The waiver temporarily lifts sanctions on Russian oil for 30 days.