WATCH: Tillerson says terrorism designation way to ‘turn pressure up’ on North Korea

Secretary of State Rex Tillerson says designating North Korea as a state sponsor of terrorism is part of a push to continue “to turn the pressure up.”

Tillerson addressed reporters at the White House on Monday after President Donald Trump announced that the U.S. is putting North Korea on America’s terrorism blacklist.

Tillerson says the message to leader Kim Jong Un is that “this is only going to get worse until you’re ready to come and talk.”

WATCH: Trump says U.S. will declare North Korea a state sponsor of terror

Tillerson noted that it had been about two months since the country tested a missile. He says, “We’re hopeful this period will continue.”

Tillerson said that while the designation was a “very symbolic move” with limited practical effects although it could close a “few loopholes” in a tough sanctions regime that was starting to bite in Pyongyang. He said anecdotal evidence and intelligence suggests the North is suffering fuel shortages, with queues at gas station, and its revenues are down.