The Defense Ministry has issued a statement countering Seoul’s rebuttal of Tokyo’s claim that a South Korean warship directed its fire-control radar at a Japanese patrol plane last month.

The ministry issued the statement Friday after South Korea earlier in the day released a video to dispute Japan’s claim over the Dec. 20 incident.

“There are different claims from our position,” the ministry said of the South Korean video. The radar lock-on is “a hazardous act that may cause unintended consequences.”

The ministry said it “intends to continue to hold necessary consultations between the defense authorities” of the two countries.

The video was released by South Korea’s Ministry of National Defense after Tokyo disclosed video footage on Dec. 28 showing the radar lock-on incident, which occurred over the Sea of Japan.

The South Korean video is “awful,” a senior Defense Ministry official said, adding, “We have to keep rebutting.”

The official noted that the South Korean video did not include radio messages sent by the Japanese patrol plane to the South Korean destroyer, which had been on the Japanese video.

Depending on the responses of South Korea, Tokyo is considering releasing radar wavelength data, usually a military secret, as additional evidence for its claim, sources familiar with the situation said.

Frustration is growing among an increasing number of Japanese government officials at South Korean President Moon Jae-in’s failure to act to resolve tensions over the incident.

Foreign Minister Taro Kono and his South Korean counterpart, Kang Kyung-wha, held telephone talks on Friday and agreed on the importance of resolving the issue at an early date. They also agreed to wait and see what developments come out of talks between the two countries’ defense authorities.

Kono also urged South Korea on Friday to prevent Japanese firms from being treated unfairly following the launch of procedures to seize assets from Nippon Steel & Sumitomo Metal Corp. over its refusal to compensate over wartime forced labor.

After speaking with Kang, Kono said that if needed, Japan will take resolute action based on international law.

“I asked (the South Korean side) to take steps quickly so Japanese firms will not suffer from treatment that is unfair and disadvantageous,” Kono told reporters.

“We believe that South Korea will take appropriate action, so we will wait and see what happens. But we want to make preparations in case we have to act resolutely based on international law,” he said, without elaborating.

Bilateral ties have deteriorated in recent weeks over rulings made by South Korea’s Supreme Court ordering Japanese companies to pay compensation for forced labor during the war.

In the wartime labor case, Nippon Steel & Sumitomo Metal had until Dec. 24 to respond to a request by lawyers for the South Korean plaintiffs to start talks on compensation. After the deadline passed, the lawyers said Wednesday they had launched a process to seize the steel-maker’s shares in Posco-Nippon Steel RHF Joint Venture, its strategic partnership with South Korean steel-maker Posco.

“We take (the request) very seriously,” Kono said after the talks, which were held at Kang’s request.