The Defense Ministry released video footage Friday that it claims shows a South Korean warship directed fire-control radar at a Japanese patrol plane last week, seeking to discredit repeated denials by Seoul.

Defense Minister Takeshi Iwaya said the 13-minutes of footage, which was made public Friday evening, would prove that despite those denials the South Korean military destroyer locked fire-control radar on a Maritime Self-Defense Force P-1 patrol aircraft in the Sea of Japan on Dec. 20.

“I’m aware there has been some speculation that it was the SDF who was acting inappropriately, but I hope this video will make it clear to the Japanese public that the SDF was acting in full accordance with international law and protocol,” Iwaya told a regular news conference.

At one point in the video, the MSDF captain is heard shouting in English multiple times at the warship, using “FC” to refer to fire control: “We observed that your FC antenna is directed to us. What’s the purpose of your act?”

The disclosure points to Tokyo’s growing impatience over its latest clash with Seoul, which has triggered a series of recriminations and further chilled bilateral ties already strained by the South Korean Supreme Court’s recent rulings against Japanese firms over wartime labor issues.

South Korea has denied that its destroyer intentionally targeted radar at the plane, accusing Tokyo of misconstruing its naval operation to rescue a North Korean ship drifting near a sea border, according to the Yonhap news agency.

Even if this assertion is true, emitting fire-control radar is, according to a statement released last week by Japan’s Defense Ministry, an “extremely dangerous act” that could be considered a prelude to an actual attack and which has the potential to spark contingencies.

On Friday, Iwaya emphasized that the footage shows the weather was “clear enough for (South Korea) to visually confirm the location of the ship” in distress on the day of the incident, casting doubt over Seoul’s initial claim that it had to activate radar to identify it.

The minister also obliquely criticized Seoul for not having offered an apology, and demanded that it take the high road, citing the “extremely important” security alliance between the two countries.

“If Japan were in South Korea’s shoes, I’m sure we would conduct thorough scrutiny of what happened and, upon finding we were wrong, penalize those responsible and apologize to the other country,” he said.

“I hope that Japan and South Korea can harness a relationship where a party at fault can say to the other, ‘We’re sorry. It won’t happen again,’ because we’re friends.”

South Korea’s Defense Ministry, for its part, responded by saying that the released video “cannot be regarded as objective evidence” of the lock-on, Kyodo News reported.

In preparing for the disclosure, the Defense Ministry muted portions of the captain’s conversation with the rest of the crew to protect what it described as sensitive information and added subtitles to give the public a better understanding of what happened.

Asked about the possibility that the editing may undermine the video’s credibility, Iwaya said the ministry had already sent a separate, fuller version of the footage to the South Korean military for examination — although this version, too, had been subject to a degree of editing to avoid exposing defense capabilities of the SDF.

On Thursday, Japan and South Korea held working-level talks via teleconference to discuss the lock-on, but the two sides remained far apart, according to Kyodo News. During this communication, Tokyo had again stressed that it found Seoul’s act “regrettable” and urged steps to prevent a recurrence, Iwaya said.

In its previous statements, the Defense Ministry had stated that the destroyer locked fire-control radar on its surveillance plane “for a certain period of time on multiple occasions,” citing its own analysis of the frequency and intensity of radio waves emitted by the warship.

South Korean sources, for their part, were quoted by Yonhap as claiming that their warship had used an optical camera to identify the “approaching” Japanese patrol aircraft.

Tokyo, however, rebuffs this allegation, with the Defense Ministry saying the MSDF plane was maintaining a “certain distance and altitude” as it flew over the South Korean ship, and “never conducted a low-level flight.”