US President Donald Trump confirmed on Tuesday that he will legally designate Mexican drug cartels as terrorist groups, in his continued mission to “wage war on drug cartels.”

In a televised interview with Fox News reporter Bill O’Reilly, Trump stated that those found to be a part or to assist these cartels will face the same penalties set out in the Foreign Terrorist Organization List. This will mean that it would be illegal for anyone to support drug cartels and could allow US military intervention without Mexico’s permission. Trump also stated that he was well underway with the process of designation and that it has been ongoing “for the last 90 days.”

Mexico, however, has “rejected” any offer for Trump to launch operations against cartels in their country. Military intervention by the US was heavily criticized by Mexico’s Foreign Minister, Marcelo Ebrand, who said:

Mexico will never allow any actions that violate its national sovereignty. We will be firm. I have let the United States know my position, as well as our plan against organized transnational crime.

The increasing tensions between Mexico and the US follow a deadly ambush in Mexico that killed nine US citizens. Victims’ family have petitioned the White House to label drug cartels as terror groups.