Trump has amped up pressure on North Korea to come to the negotiating table with sanctions. North Korea, however, has undercut such sanctions for years with cyber-robberies that have targeted more than $1 billion. Those cyberattacks, although lacking the flash of a bomb, must also be part of any deal that the Trump administration makes with North Korean dictator Kim Jong Un.

Financial crimes mean that even when faced with tough sanctions, North Korea can undercut their intention by simply hacking a victim and requesting large transfers. With such an option, buttressed by countries that are willing to continue shipments of important resources regardless of sanctions, North Korea is in a far less controllable position.

This impacts the success of current negotiations and of any agreement that has additional sanctions as a repercussion for violating its terms. As long as North Korea possess its cyber-theft infrastructure and faces little pressure to end its use, those sanctions aren’t as effective of a deterrent and potentially undercut any future deal.

In negotiations, the Trump administration must consider this.

North Korea has stopped its missile tests but not its cyberattacks. Although cyber-robberies aren’t as exciting as missiles, they are still attacks and are of great value to the Kim regime. Indeed, cyberattacks, including direct robberies, ransomware attacks, or theft from cybercurrency exchanges, are a great deal more lucrative than blasting missiles into space.

In September, the Trump administration started to push back on these sorts of attacks with its “name and shame” approach to outing those working the Kim’s dictatorship. That campaign, however, has had little impact on the frequency of attacks.

Preventing them requires a more aggressive approach. Making it clear that these attacks are considered evidence of bad faith and that negotiations with the U.S., including, for example, a second meeting with Trump, would only take place if they stop would be a good step.

Another good move, highlighted by Michael Daniel, the CEO of Cyber Threat Alliance, is targeting North Korea’s international networks. Since the isolated dictatorship doesn’t have the domestic Internet capabilities for such hacks, they are launched from abroad. That would mean that the U.S. could pressure other countries where the attacks originate, or that money is laundered through, to arrest and hand over North Korean actors.

Robberies and ransomware attacks, such as WannaCry, are key tools in North Korea’s arsenal. In his eagerness for a deal on denuclearization, Trump must recognize that ending the threat posed by North Korea requires consideration of cyberattacks too.