President Donald Trump's move to re-list North Korea as a state sponsor of terrorism could undermine diplomatic efforts to halt the rogue state's nuclear aggression.

Pyongyang was previously on the list of terrorist states but it was removed in 2008 as China, Japan, Russia, South Korea and the U.S. held talks with the isolated country on disabling its nuclear facilities. The talks eventually broke down but North Korea stayed off the list, until now.

The international community, including Seoul and Tokyo, support Trump's measure, saying the relisting will pressure Pyongyang to denuclearize. But experts aren't so sure: Many said the act, which will impose further sanctions on dictator Kim Jong Un's regime, sends mixed messages about Washington's intentions.

The world's largest economy has a policy of "maximum pressure" against the nuclear-armed nation, a strategy underpinned by economic penalties and trade restrictions with the aim of forcing Pyongyang back to the negotiating table. Monday's action, however, isn't seen as conducive to that line of thinking.

Pressure is presumably intended to lead to some type of diplomacy, but the designation will only confuse North Korea and make it difficult for its leadership to respond to future diplomatic signals, explained Daniel Sneider, visiting scholar at Stanford University's Shorenstein Asia-Pacific Research Center.

"I really don't understand what the point of [relisting] is if diplomacy is the goal," he said. "It doesn't suggest to me like this is a step meant to lead to talks with the North Koreans."