President Trump says he is going after big oil companies, accusing them of gouging prices at the gas pump.

The president said in a social media post that he has instructed the Department of Justice to investigate oil companies, arguing current gas prices do not reflect falling oil costs.

This comes amid continued peace talks between the U.S. and Iran, and the planned reopening of the Strait of Hormuz, through which 20% of the world's oil travels.