US plans to impose additional sanctions against Iran, Donald Trump's national security advisor John Bolton warned on Monday.

Trump administration is not "simply going to be content" with the level that existed under former President Obama, The Hill reported.

Bolton's comments came as the U.S. reimposed its final round of sanctions against Tehran after leaving the Iranian nuclear deal in May. 

"We’re gonna have sanctions that even go beyond this," Bolton said on Fox Business. "We’re not simply going to be content with the level of sanctions that existed under Obama in 2015." 

"More are coming," he pledged, adding, "We are actually going to have very strict, very tight enforcement of the sanctions that exist."