In this June 1, 2018 photo, flags of the Group of Seven (G7) nations and the European Union flag fly over the Fairmont Le Manoir Richelie hotel, the location for the G7 summit, in La Malbaie, Quebec. (ALICE CHICHE / AFP)

Japan has told the US it opposes the participation of Republic of Korea (ROK) in a Group of Seven summit this year, Kyodo News reported, citing more than one source related to Japanese and US diplomacy.

The Japanese government objected on the grounds of differences in policy on DPRK among other things, Kyodo reported this weekend. Japan also wants to maintain its status as the only Asian country in the group, the news agency said

The Japanese government objected on the grounds of differences in policy on the Democratic People's Republic of Korea (DPRK) among other things, Kyodo reported this weekend. Japan also wants to maintain its status as the only Asian country in the group, the news agency said.

ALSO READ: S. Korea's Moon tells Trump he would accept invitation to G7 summit

Japanese Chief Cabinet Secretary Yoshihide Suga told reporters Monday it was important to maintain the framework of the G-7 as it is. He added that it was up to the US, this year’s host, to decide on arrangements for the next meeting. The G-7 frequently invites other nations to take part as guests.

Japan and ROK have seen relations fall to their lowest levels in years due to renewed disputes arising from Japan’s 1910-1945 colonial rule over the Korean Peninsula. The tensions have clouded trade links and joint security for the two US allies, who both face a threat from DPRK.

Japanese Foreign Minister Toshimitsu Motegi told national broadcaster NHK on Sunday that it was important to maintain the current G-7 framework and that this was the consensus view, Kyodo said.

ROK's Foreign Ministry said in a statement Monday that it would refrain from commenting on the reports, and Japan’s Ministry of Foreign Affairs didn’t immediately respond to a request for comment.

US President Donald Trump said in May he was considering inviting Russia, ROK, Australia and India to an extended G-7 leaders meeting, alongside the seven member countries, saying the existing set-up was outdated.

Trump said the meeting could be held the weekend before or the weekend after the United Nations General Assembly, which is scheduled to open - potentially virtually, not in person - on Sept 15 and run through Sept 30.

“Maybe I’ll do it after the election,” Trump said in late May. “I think a good time would be before the election.” The US presidential election is Nov 3.

READ MORE: Trump postpones G7 summit, seeks to expand list of invitees

The current G-7 member countries are the US, Japan, Germany, Canada, the UK, France and Italy. Several countries are opposed to the idea of including Russia, which was suspended from what was then the Group of Eight major economies in 2014 after its annexation of Crimea. ROK is a member of the Group of 20.