Prime Minister Yukio Hatoyama and South Korean Foreign Affairs and Trade Minister Yu Myung Hwan agreed Wednesday to coordinate closely on issues related to North Korea along with the United States, and to strengthen bilateral ties in a broad range of areas, Japanese officials said.

Yu also met with Chief Cabinet Secretary Hirofumi Hirano and Foreign Minister Katsuya Okada. He invited Hatoyama to visit South Korea "at an early date," Hirano told a news conference.

Hirano said he thanked Yu for the offer but did not elaborate on when Hatoyama will visit. There is speculation Hatoyama may go to South Korea on Oct. 9, a day before a summit that China will attend.

"Through shuttle diplomacy, we would like to deepen the friendship between leaders as well as work closely at the ministerial level," Yu said to Hatoyama at the start of their meeting in the prime minister's office.

Yu was referring to one or more reciprocal visits a year by the nations' leaders. The visits were agreed on in December 2004 between Prime Minister Junichiro Koizumi and President Roh Moo Hyun.

Hatoyama and Yu agreed to make the bilateral relationship "future-oriented and unwavering" in various areas, including economics and the environment, Foreign Ministry officials said.