SEOUL, June 17 (Yonhap) -- South Korea's rival political parties expressed caution Monday over North Korea's recent proposal for high-level talks with the United States, saying the South should not be left out of the picture. The North's proposal came Sunday, five days after its planned high-level talks with Seoul broke down due to a dispute over the rank of the chief delegate from each side. Pyongyang proposed the two sides discuss security and nuclear issues. However, Washington urged the communist nation to first live up to its denuclearization commitments.

Police on Monday searched the head offices of a used-tire exporter in Tomakomai, Hokkaido, and a trading company in Fukuoka on suspicion of illegally exporting used tires to North Korea, according to investigative sources. A joint Hokkaido-Fukuoka investigation team suspects that the companies sent used tires to North Korea via Dalian, China, without approval from the Japanese trade minister. The names of the companies were not immediately known.

A day after North Korea called for unconditional high-level dialogue with the United States, the Japanese government's top spokesman said Pyongyang should first show a willingness to discuss denuclearization. "We do not speculate what North Korea's intentions are but any dialogue should lead to denuclearization, and North Korea should first show its sincere attitude toward denuclearization," Chief Cabinet Secretary Yoshihide Suga said during a press conference on Monday.

SEOUL, June 17 (Yonhap) -- South Korea is studying the possibility of holding trilateral talks with top diplomats from the United States and China on the sidelines of a regional security conference in Brunei later this month, a diplomatic source said Monday. The move comes as North Korea issued a surprise proposal for talks with the U.S. on Sunday, after months of raising tensions on the Korean Peninsula following its third nuclear test early this year.