Japanese Foreign Minister Hirofumi Nakasone said on Friday he will visit South Korea next week as signs grow that North Korea is planning a long-range missile.
Nakasone said he will meet his counterpart Yu Myung-Hwan and pay a courtesy call to President Lee Myung-Bak during his visit next on Tuesday and Wednesday.
Officials in Seoul and Washington say there are signs North Korea is preparing to test the Taepodong-2 missile, which has a range of 6,700 kilometres (4,100 miles) and could theoretically reach Alaska.
The North carried out long-range missile tests in 1998 and 2006, sparking international condemnation and frightening Japan.
The North, which is fiercely hostile to Seoul's conservative government, announced last week it has scrapped all peace agreements with the South including one covering the Yellow Sea borderline.
Japan, which North Korea regards as an arch enemy, has also been pressing Pyongyang to give a full account of Japanese nationals kidnapped to train North Korean spies in the 1970s and 1980s.
The meeting was set up just days before new US Secretary of State Hillary Clinton goes on a tour of East Asia from February 15.
Christopher Hill, who was Washington's top nuclear negotiator with North Korea, will travel with Clinton to Asia.
Japan and South Korea have been trying to forge closer ties despite lingering tension over their wartime past. Prime Minister Taro Aso visited Seoul last month.