North Korea’s latest nuclear test is darkening the outlook for cross-border relations, leaving little room for the Park Geun-hye administration to improve ties and cement its diplomatic and security legacy.

The underground explosion caught Seoul off guard, as it came only days after North Korean leader Kim Jong-un stressed the significance of the Aug. 25 inter-Korean fence-mending agreement on Friday, vowing to continue talks and urging Seoul not to commit any “retrograde” behavior that could dampen the mood for dialogue.

In her first Cabinet meeting this year Tuesday, Park upheld Kim’s speech, instructing her aides to make constant efforts to “normalize” cross-border ties. 

While the Defense Ministry apparently had not foreseen the test, many state-run think tanks had predicted in their recent 2016 outlooks that Pyongyang would not press ahead with it this year.

The relationship has already grown frosty since their first formal meeting in years broke down early last month due to irreconcilable differences in their positions on stalled tours to a North Korean mountain resort, reunions of separated families and other issues.

The atmosphere is expected to reactivate the longstanding vicious circle of international sanctions and possibly another provocation resulting in a months-long freeze in bilateral and multilateral dialogue.

The experiment will likely further stifle any efforts to better relations with the unruly regime and rather harden the U.S. and other countries’ approach, especially with Seoul gearing up for a general election, Washington for a presidential vote and China and Russia remaining bogged down by domestic challenges.

“Through the test, the North appears to have intended to make the U.S. give up its ‘strategic patience’ and pursue direct, bilateral talks, during which it would call for an end to South Korea-U.S. joint military exercises and the signing of a peace agreement. But I doubt that Washington will change course and offer dialogue,” said Chong Seong-chang, head of unification strategy research at the Sejong Institute.

“They may have also sought to heap pressure on the Park administration to relinquish its ‘unification preparations’ and ‘unification diplomacy’ and get more progressive about cooperation with the North. Yet due to the experiment, any improvement of inter-Korean ties is unlikely now within her presidency.”

By Shin Hyon-hee (heeshin@heraldcorp.com)