Japanese lawmakers are expected to go ahead with their planned trip to an island near South Korea’s easternmost islets of Dokdo on Monday, upping tensions as the Seoul government plans to ban them from entry.

Despite South Korea’s official announcement that it will bar the Tokyo politicians from entering its land, three lawmakers of Japan’s opposition Liberal Democratic Party said they would go ahead with a four-day trip.

A top aide to President Lee Myung-bak left for the eastern islands of Ulleungdo and Dokdo Sunday, vowing to “stay on guard” until the Japanese legislators return to their own country.

“There is no room on these islands for any Japanese lawmakers,” Lee Jae-oh, a lawmaker of Seoul’s ruling party and also President Lee’s special affairs minister, said on his Twitter account before heading off to the island of Ulleung for a four-day trip.

“I will stay there until they return to their country.”

Tokyo has for years laid territorial claims over the South Korean volcanic islets ― located about 90 kilometers east of Ulleungdo ― often posing a stumbling block to mending ties with Korea, which was under Japanese colonial rule from 1910-45.

Dokdo, called Takeshima by the Japanese, is a group of small islets that lie in rich fishing grounds in the East Sea which also are believed to contain large gas deposits.

Dismissing Tokyo’s claim as nonsense as South Korea reclaimed sovereignty over the mainland as well as several islands around the peninsula after independence, Seoul has had Coast Guard officers stationed in Dokdo since 1954. Two citizens live on the islets.

The latest dispute erupted when the Japanese politicians said they would visit the island of Ulleungdo to see for themselves “how South Koreans feel” about the issue that has been straining ties between the two neighboring countries for six decades.

South Korea sees the high-profile trip to the island as an attempt by Japan to renew its longstanding territorial claims and to win support from the right wing in Tokyo. South Korea has for years kept a policy of not strongly responding to Tokyo’s claims, believing it has no reason to draw international attention to an island that clearly belongs to the country.

South Korea has, however, lodged a formal protest with the top Japanese envoy in Seoul against the planned visit and warned that the lawmakers’ safety cannot be guaranteed.

Still, Yoshitaka Shindo, a lawmaker of the conservative opposition party, said in a news conference over the weekend that he and his two fellow legislators would travel to South Korea today, warning that banning them from entry would have a negative impact on bilateral ties.

In a rare move to take sides with its southern rival, North Korea denounced Saturday the Tokyo politicians move to visit Ulleungdo despite Seoul’s warning.

“The Japanese reactionaries’ recent moves are serious issues not to be tolerated by the Korean nation as they revealed once again their ambition to seize inalienable parts of the territory of Korea,” Pyongyang’s official Korea Central News Agency said.

The North Korean media outlet also rapped South Korean authorities for taking a “passive approach” towards Japan due to fear of arousing anti-Japanese sentiment.

“It is due to the present South Korean ruling forces’ servile attitude toward Japan ... that the Japanese reactionaries are set to visit the Tok Islets like their own land,” KCNA said.

Leaving for Ulleungdo on Sunday, presidential aide and veteran South Korean legislator Lee said he would meet with local residents and coast guards on the East Sea islets and together condemn the Japanese politicians’ move. Lee made a similar trip to Dokdo in April.

By Shin Hae-in and news reports  (hayney@heraldcorp.com)