By Joyce Lee and Kiyoshi Takenaka
SEOUL/TOKYO (Reuters) - Japan is likely to skip an international fleet review in South Korea next week, Japanese media on Friday, after Seoul asked Tokyo to reconsider flying its "Rising Sun" flag on a warship, the latest spat over the countries' colonial history.
Japan's relations with both South and North Korea have long been strained by lingering resentment over its colonisation of the peninsula, territorial rows and the issue of girls and women forced to work in Japan's wartime brothels.
Chief Cabinet Secretary Yoshihide Suga told a news conference that Japan's defence ministry was considering whether to take part, but public broadcaster NHK said Tokyo had already told Seoul it was unlikely to do so.
Many people in both Koreas see the red-and-white flag as a symbol of Japan’s past military aggression and its colonisation of the Korean peninsula from 1910 to 1945.
"The 'Rising Sun' flag is a war-crime flag that the 20th-century Japanese imperialists used when executing their barbaric invasions into our nation and other Asian nations," North Korea's state-controlled Uriminjokkiri website said.
"Planning to enter flying the 'Rising Sun' flag is an unbearable insult and ridicule to our people."
In South Korea, articles about the controversy are among the most widely read on social media, with the president's office receiving 250 petitions for the Japanese ship to be barred.
On Friday, the South Korean Navy said Japanese naval ships flew the ensign when they participated in fleet reviews in 1998 and 2008, but it had asked all ships at this year's event to display national flags and the South Korean flag.
The "Rising Sun" ensign, used by the Japanese Imperial Navy in campaigns around Asia and the Pacific before and during World War Two, was adopted by the Maritime Self-Defence Force in 1954.
Variations of the flag are used by the Ground Self-Defence Force and on the fatigues of some Japanese sailors, but some South Koreans liken it to Nazi symbols such as the swastika.
Japanese officials had signalled the flag would be flown, despite the protests.
"Hoisting of the Maritime Self-Defence Force ensign is required by law," Katsutoshi Kawano, the chief of staff of the Self Defence Forces, told reporters on Thursday.
"Members take pride in the ensign, and we will never go there with the flag unhoisted."
South Korea's foreign ministry had "conveyed our stance that the Japanese side should fully consider the Rising Sun flag's emotional connotation to our people," Foreign Minister Kang Kyung-wha said.
Japan is a key player in United States-led efforts to isolate and punish North Korea over its nuclear weapons and ballistic missiles.
But it has remained a major target of criticism, despite warming ties between Pyongyang and Seoul as the North's leader Kim Jong Un engaged in a flurry of diplomacy this year, when he also met leaders of the United States and China.
Japan and South Korea often trade barbs over disputed islands known as Takeshima in Japan and Dokdo in Korea.
(Additional reporting by Tim Kelly in TOKYO; Additional writing by Linda Sieg in Tokyo; Editing by Clarence Fernandez)