Japan has announced that it scrambled fighter jets in response to what Tokyo called a “provocation” of Russian and Chinese aircraft near its airspace.

This news comes as the country hosts a meeting of world leaders for the first-ever informal gathering of the Quad nations: Japan, the US, Australia and India.

Announcing the news during a virtual press conference, Japanese defense minister Nobuo Kishi said the move was planned to coincide with this meeting. 

Kishi said that he expressed “grave concerns” over the aircraft entering Japanese airspace, adding that a minimum of two Chinese bombers joined two Russian bombers in the Sea of Japan, making “a joint flight to the East China Sea.”

The planes in question were identified as Tu-95 strategic bombers and Chinese Xian H-6 jets.

"After that, a total of four aircraft, two presumed new Chinese bombers – which replaced the two Chinese bombers, and two Russian bombers, conducted a joint flight from the East China Sea to the Pacific Ocean," the defense minister added as quoted by Independent.co.uk.

The exercise was later confirmed by Moscow, who said that the planes carried out a joint patrol exercise in the region on Tuesday. 

Officials later confirmed that the joint drill lasted for 13 hours. 

South Korea’s military has also announced it scrambled fighter jets after what is presumed to be the same Chinese and Russian warplanes entered its air defense zone on Tuesday, Reuters reports. 

It was reported by South Korea’s Joint Chiefs of Staff that the aircraft entered and left the Korea Air defence Identification Zone (Korea ADIZ) several times throughout the day. 

ADIZ is different from airspace. It is an area in which countries can demand a foreign aircraft to identify themselves. There are no international laws underpinning ADIZs.

Moscow has previously said they do not recognize the ADIZ in Korea. Beijing has also stated that as the area is not linked to a territory all countries should be given the opportunity to enjoy freedom of movement there.