The New Zealand air force has begun an international submarine-hunting exercise with forces of the Republic of Korea (ROK) in the Sea of Japan, the New Zealand Defense Force (NZDF) announced Thursday.

The P-3K2 aircraft from the Royal New Zealand Air Force (RNZAF) 5 Squadron arrived at Pohang to join the ROK navy's Air Wing 6 last week for Exercise Rokkiwi, a biennial anti-submarine warfare exercise hosted by the South Korean Navy.

They had practiced tactical level cooperation and coordination with ROK aircraft and United States Navy P-3Cs from the 7th Fleet, based in Japan, said a statement from the NZDF.

Wing Commander Aaron Benton said it was the first exercise involving the RNZAF's upgraded P-3K2.

"As the South Korean Navy has submarines, this is a fantastic chance to test our anti-submarine warfare capabilities," Benton said in the statement.

"South Korea is also upgrading its P-3 fleet so we are able to create synergies and learn from each other as to what things work and what don't."