North Korea slammed the U.S. on Thursday for seeking alternatives to the U.N. Panel of Experts monitoring DPRK sanctions, claiming that the country only “grows stronger before harsher sanctions and pressure.”

The DPRK’s statement came as the Panel is set to dissolve at the end of this month unless the U.N. Security Council can reach an 11th-hour deal to extend its mandate, after Russia vetoed a renewal in March.