SEOUL, South Korea — President Trump’s re-designation of North Korea as a state sponsor of terrorism may have dashed cautious hopes in the region that talks and diplomacy would replace escalating tensions and bellicose threats, analysts said on Tuesday.

Despite a two-month hiatus in North Korea’s weapons tests, Mr. Trump has held to his policy of “maximum pressure,” restoring North Korea on Monday to Washington’s list of terrorism-sponsoring states, along with Iran, Sudan and Syria. The move, he said, would be followed by “the highest level of sanctions.”

On Tuesday, Treasury Department officials announced a new round of sanctions aimed at disrupting the North’s nuclear and ballistic missile program. They were levied against Chinese trading companies and several North Korean shipping vessels and companies, freezing their assets and prohibiting Americans from engaging in transactions with them.

Secretary of State Rex W. Tillerson had described the sanctions on Monday as extensions of existing prohibitions. “It may, though, disrupt and dissuade some third parties,” he said. “This will close a few additional loopholes off.”

Analysts said they doubted that new sanctions would make any real difference on the already heavily penalized country. If anything, they said, the designation will make diplomacy more difficult without increasing Washington’s leverage, warning that North Korea will probably take the naming and shaming as another reason to stick to its hard-line policy of developing and testing nuclear weapons and intercontinental ballistic missiles.