Prime Minister Junichiro Koizumi toughened his diplomatic stance toward China and South Korea on Monday, saying the two countries are trying to use issues related to his visits to Yasukuni Shrine as "a diplomatic card" against Japan.

Koizumi's criticism came when he was asked about China's decision to cancel an annual trilateral summit involving Japan, China and South Korea usually held on the sidelines of gatherings of the Association of Southeast Asian Nations.

"Yasukuni will no longer work as a diplomatic card," Koizumi told reporters at the Prime Minister's Official Residence. "Even if China and South Korea try to make it a diplomatic card, it will be useless."

China announced Sunday it will put out of the trilateral summit next week, citing "the current atmosphere and conditions," apparently referring to the strained ties between Japan and its two neighbors over Koizumi's repeated visits to the Shinto shrine.

Koizumi said he is still willing to meet with leaders of the two countries. "It is up to China," Koizumi said. "I believe it is the criticizing side that is wrong."