South Korean Foreign Minister Kim Sung-hwan warned yesterday of signs of a rightward shift in Japanese politics, including an increasingly aggressive stance on territorial issues.
Kim's remarks followed last week's decision by Japanese Prime Minister Yoshihiko Noda to dissolve parliament and call a general election next month.
"Overall, the political situation in Japan is showing signs of a rightward shift and some say Japan is increasingly becoming nationalistic," Yonhap news agency quoted the minister as telling a business forum in Seoul.
"We are closely watching the situation and will be prepared to cope with it," Kim said. "Japan is becoming more conservative and aggressive over territorial matters and [we] need to watch out for that."
Early polls suggest Japan's main opposition Liberal Democratic Party (LDP), headed by former premier Shinzo Abe, will emerge as the single biggest party in the December 16 election.
On Wednesday the LDP unveiled a series of policy priorities, including pledges to consider establishing a permanent presence on uninhabited Tokyo-controlled islands at the centre of a dispute with China.
It also promised a review of the self-imposed ban on defending allies, raising the possibility of Japanese troops returning fire if US forces were to come under fire.
South Korea is currently locked in its own territorial dispute with Japan over islands midway between the two countries.
"Again, I would like to make it clear that we will not compromise with Japan with regard to territorial and history-related issues," Kim said.
The prospect of the hawkish Abe being handed another term as prime minister is viewed with some alarm in South Korea.