Two Japanese ministers visited a war shrine at the center of diplomatic friction with South Korea and China, shrine officials said Sunday, a move that could cast a pall on the planned summit for their leaders.

Justice Minister Mitsuhide Iwaki and Internal Affairs and Communications Minister Sanae Takaichi visited the Yasukuni Shrine, a day after Japanese Prime Minister Shinzo Abe sent a symbolic offering to the war shrine in Tokyo to mark its annual autumn festival.

"I expressed my heartfelt gratitude to those who sacrificed themselves for the country," Japan's Kyodo news agency quoted Takaichi as saying after the visit. "It is a matter that has nothing to do with diplomatic relations."

In 2013, Abe paid his respects at the shrine. He has since refrained from visiting there, instead sending "masakaki" tree offerings during the country's spring and fall festivals.

The shrine is viewed by Seoul and Beijing as reflecting Tokyo's militaristic past. It honors around 2.4 million war dead of Japan, including 14 Class-A war criminals.

The Japanese move came as President Park Geun-hye prepares to host the leaders of China and Japan for a trilateral summit in early November.

U.S. President Barack Obama said Friday in a joint news conference with Park in Washington that the trilateral summit "can be another step forward in building positive relations between South Korea, Japan and China."

A trilateral summit has not been held since May 2012 due to tensions over Japan's attempts to whitewash its wartime atrocities and colonial occupation.

Japan ruled the Korean Peninsula as a colony from 1910 to 1945 and controlled much of China in the early part of the 20th century. (Yonhap)