Tokyo is preparing to arrange a summit between Prime Minister Shinzo Abe and North Korean leader Kim Jong Un in September in Russia, after Kim expressed his readiness to meet with Abe during his meeting with U.S. President Donald Trump, a government source said Thursday.

The two leaders could meet in Russia’s Far Eastern city of Vladivostok on the sidelines of the Eastern Economic Forum, which Abe is expected to attend. Kim has also been invited by Russia to take part.

Russian President Vladimir Putin recently invited Kim to make his first trip to the country since taking power in late 2011, and attending the forum, which is scheduled for Sept. 11-13, could be one opportunity.

During the summit in Singapore on Tuesday, Kim said there are possibilities for him to meet with Abe and he is “open” to doing so, according to the source.

Following the remarks, Tokyo is expected to launch full-fledged preparations to realize the first Japan-North Korean summit since 2004 in an attempt to settle the issue of Japanese nationals abducted by Pyongyang in the 1970s and 1980s. The Abe administration has viewed the matter as one of its priorities.

Abe will likely tell Kim that Japan is ready to settle the tumultuous past between the two countries, normalize bilateral ties and provide economic support after the comprehensive resolution of outstanding issues concerning North Korea, including its nuclear and missile programs and the abductions. Japan occupied the Korean Peninsula between 1910 and 1945.

Although the Trump-Kim summit was focused on the denuclearization of the Korean Peninsula, the U.S. president brought up the abduction issue at Abe’s request and conveyed Japan’s stance, which is based on the 2002 Japan-DPRK Pyongyang Declaration, according to the source. DPRK is an abbreviation of North Korea’s formal name.

Kim did not repeat his country’s long-held position that the abduction issue has been resolved, Koichi Hagiuda, a lawmaker close to Abe, told reporters Wednesday after meeting with the prime minister.

Abe was briefed on the summit by Trump over the phone.

“Taking the opportunity of the U.S.-North Korean summit, Japan is determined to face North Korea directly and resolve the issue,” Abe said during a meeting at his office with a group representing abductees’ families Thursday afternoon.

During the meeting, Shigeo Iizuka, who heads the group, asked Abe not to rush into such a summit, saying, “I believe it is still early for the prime minister to (meet with Kim) and negotiate various matters, while nothing is decided.”

Abe did not mention the schedule for Japan’s planned negotiations, according to a meeting participant.

The Foreign Ministry is dispatching Fumio Shimizu, deputy director general at its Asian and Oceanian Affairs Bureau, to a security forum in Ulaanbaatar, where there will be an opportunity for contact with North Korean officials attending the two-day event through Friday.

Japanese and North Korean leaders have not met since Prime Minister Junichiro Koizumi held talks with Kim’s father, Kim Jong Il, in Pyongyang 14 years ago.

Japan officially lists 17 of its citizens as having been kidnapped by North Korean agents and suspects the North’s involvement in many more disappearances of Japanese nationals.

Of the 17, five were repatriated in 2002 following Koizumi’s first talks with Kim. Pyongyang claims eight of the abductees have died and the other four never entered the country.