Did not make an apology: Russia on airspace violation dispute with South Korea

Russia's embassy in Seoul on Wednesday denied that Moscow had formally apologised over an alleged airspace violation the previous day after South Korea said that Russia had expressed "deep regret" while blaming an equipment malfunction.

A Russian military aircraft entered airspace near a group of islets claimed by both South Korea and Japan on Tuesday, during a long-range joint air patrol by Russian and Chinese aircraft, according to South Korea and Japan, which both scrambled fighter jets in response.

South Korean warplanes fired flares and hundreds of warning shots near the Russian aircraft, and the incident triggered a round of diplomatic protests by countries in the region.

An unidentified Russian military attache in Seoul told South Korean officials that the military plane appeared to have "entered an unplanned area due to a device malfunction", said Yoon Do-han, a press secretary at South Korea's presidential office.

"Russia has conveyed its deep regret over the incident and said its defence ministry would immediately launch an investigation and take all necessary steps," Yoon said.

"The officer said such a situation would have never occurred if it followed the initially planned route."

It was not immediately clear if Yoon meant the attache was speaking officially on behalf of the Russian government but Russia's embassy in Seoul denied that it had apologised.

"The Russian side did not make an official apology," the embassy in Seoul said, adding it had noted many inaccuracies in the comments by South Korea, Interfax reported.

Russia's public statements on the issue have not mentioned any technical problems, nor has Russia announced any investigation or acknowledged a violation of South Korean air space.

South Korea's defence ministry said that after initially admitting a possible mistake and expressing regret on Tuesday, Russian officials on Wednesday sent South Korea an official document stating that its aircraft did not violate any air space.

WATCH: Russia expresses regret over South Korea airspace violation

Russia also accused South Korean pilots of threatening the safety of Russian aircraft.

An official at South Korea's defence ministry told reporters on Wednesday that it believed the intrusion could not have resulted from a system error.

He did not elaborate but said the two countries would hold working-level talks to discuss a Russian request to share information on the incident.

The incident came at a delicate time for a region that has for years been overshadowed by hostility between the United States and North Korea and has recently seen a flare-up in the tension between South Korea and Japan.

While troops and naval ships from Russia and China have taken part in joint war games before, they have not conducted such air patrols in the Asia-Pacific region together, according to Russia's Ministry of Defence.

China's defence ministry said on Wednesday that China and Russia did not enter territorial sky of any other country during their joint patrols on Tuesday.

South Korea and Japan scrambled fighter jets because both claim sovereignty over the disputed islets called Dokdo in Korea and Takeshima in Japan.

The two US allies are mired in a deepening political and trade dispute, which fanned concerns that it might undercut three-way security cooperation to fend off North Korea's nuclear threats.

The incident also coincided with the visit of the US national security adviser John Bolton to South Korea.

Bolton and his counterpart, Chung Eui-Yong, discussed the airspace breach during a meeting on Wednesday and vowed close consultations in case of more such incidents, South Korea's presidential Blue House said in a statement.