A Japanese daily reports that Japan was unable to contact North Korea on the sidelines of a global conference in Mongolia but will try again during another international event slated for late July.

According to the Mainichi Shimbun newspaper, Tokyo sent a Foreign Ministry official to a two-day security forum held in Mongolia from Wednesday in an attempt to make contact with North Korea. However, Pyongyang didn't participate in the conference.

The Japanese government had hoped to relay Prime Minister Shinzo Abe's willingness to hold a summit with North Korean leader Kim Jong-un "without conditions." 

The newspaper reported that Tokyo will continue efforts to reach out to Pyongyang, including at ASEAN meetings to be held in Thailand around late July or early August.

A senior Japanese Foreign Ministry official was quoted as saying that North Korea has stopped engaging in talks with other countries since the collapsed summit between leader Kim and U.S. President Donald Trump in February.

The Mainichi pointed out that according to the Mongolian government, Pyongyang usually fields officials to the Ulaanbaatar Dialogue, an annual conference on Northeast Asian security, and informed it would attend this year but pulled out at the last second.