South Korea’s Defense Ministry invited North Korea’s vice minister-level officials Friday to attend its annual high-level security forum, slated for September, setting the stage for cross-border defense dialogue.

The invitation came the day after the two sides failed to compromise over the wages of North Koreans working in the joint industrial complex in Gaeseong and other issues concerning the complex at their first meeting in more than a year.

“Via the western military communication line, we have sent a message to the North’s Ministry of the People’s Armed Forces to invite its vice minister-level officials to the Seoul Defense Dialogue,” a senior official at Seoul’s Defense Ministry told reporters on condition of anonymity.

“Should the North accept our invitation, there could be a bilateral meeting on its sidelines. We hope that the North will join our efforts to promote understanding and trust among nations in the Asia-Pacific region through this forum.”

The number of the North’s vice minister-level officials of the ministry is said to be five to six. The invitation message was sent under the name of South Korea’s Vice Defense Minister Baek Seung-joo, the official explained.

The three-day SDD is scheduled to take place from Sept. 9. Officials and experts from at least 32 nations, including the U.S., China and Japan, and four international organizations such as the U.N. are set to attend the forum.

It was set up in 2012 with the aims of boosting cooperation and exchanges among vice minister-level defense policymakers in the region and civilian security experts, and promoting peace and stability on the peninsula and beyond.

Meanwhile, the two Koreas accused each other of refusing to budge during Thursday’s talks over the wages of North Korean workers and other issues about the complex, the only symbol of inter-Korean economic cooperation.

“(North Korea) has yet to throw away its hitherto inflexible stance over the wages and the three problems (of passage, communication and customs clearance),” Seoul’s Unification Ministry spokesperson Jeong Joon-hee told reporters.

He added that during the talks, Seoul sought to show “sufficient flexibility” in its stance over the wages and at the same time, tried to bridge differences over other issues including the so-called three problems.

The wage issue erupted in February as the North unilaterally raised the minimum wage for some 55,000 North Korean workers by 5.18 percent to $74, disregarding the agreed-upon wage increase ceiling of 5 percent.

During Thursday’s meeting, the North repeated its position that the increase in the minimum wage is an issue concerning its sovereignty, while Seoul argues it cannot accept any unilateral decision by the North.

Expressing frustration, Park Chol-su, the head of North Korea’s delegation for the meeting, said, “We don’t need such a meeting in the future. ... Today, I really felt that the joint meeting was a very unnecessary apparatus.”

By Song Sang-ho (sshluck@heraldcorp.com)