The mother of a girl who has come to symbolize Japanese citizens abducted by North Korea urged the government Wednesday to intensify efforts to return her daughter, as she voiced frustration at the lack of progress four decades after the teenager was kidnapped.

"Although she is in a country close to us, why can we not rescue her for such a long time?" Sakie Yokota, the 81-year-old mother of Megumi, who was forcibly taken at age 13, told a press conference on the 40th anniversary of her disappearance.

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With dialogue on the abduction issue between Tokyo and Pyongyang stalled, Yokota voiced impatience.

"We believed the government had been thinking hard, but the families (of the abduction victims) now wonder if it was the right decision to trust it," she said when asked about the government having failed to resolve the issue. Sakie said she has taken all possible actions to demand the government get the abductees back.

Megumi's father Shigeru, 85, joined Sakie in attending the press conference held at their apartment in Kawasaki, southwest of Tokyo. It was a rare appearance by him as he currently spends half the week in a day-care facility for the elderly.

Shigeru made brief comments at the end of the press conference but it was hard to catch them even for his wife sitting next to him.

Their daughter was snatched by North Korean agents on Nov. 15, 1977, when she was on her way home from school in Niigata Prefecture on the Sea of Japan coast. She is the most well-known of the Japanese abducted by Pyongyang in the 1970s and 1980s.

The anniversary comes as tensions have intensified due to Pyongyang's nuclear and missile threats, with Tokyo agreeing with Washington to put more pressure on North Korea.

Families of the abduction victims have pinned high hopes on Prime Minister Shinzo Abe as he has repeatedly said rescuing the abductees is a "top priority" for his Cabinet.

In 2014, Tokyo and Pyongyang reached an accord in Stockholm on principles for negotiations toward the settlement of their key issues, including the abduction problem, and agreed to report the results of North Korea's own investigation into Japanese abductees. But the negotiations have been stalled with Pyongyang repeatedly postponing the reporting.

"I hope she is doing well. ... I think we will not live so long (to see her again)," Sakie said of her 53-year old daughter. "I want to meet her even for an hour."

The plight of North Korean abduction victims and their families has drawn the attention of U.S. President Donald Trump.

The U.S. leader raised the issue during his first general debate address at the U.N. General Assembly in September. He also vowed to make efforts to help resolve the issue in his meeting with families of the abductees, including Sakie, in Tokyo last week during his five-nation Asian tour.

North Korea has claimed that Megumi committed suicide in the 1990s after giving birth to a daughter. Pyongyang handed over to Japan what it claimed were cremated remains of Megumi in 2004. But DNA tests conducted in Japan found the ashes were not hers.

In 2014, the Yokotas secretly met Megumi's daughter Kim Eun Gyong, now 30, in the Mongolian capital, Ulan Bator.

The Japanese government officially lists 17 citizens as having been abducted by North Korean agents and suspects Pyongyang's involvement in other disappearances of Japanese nationals.

Of these 17, five were repatriated in 2002 following then-Prime Minister Junichiro Koizumi's visit to North Korea for talks with then-leader Kim Jong Il, during which Kim admitted his country's involvement in abductions. Pyongyang has claimed eight of the abductees, including Yokota, have died and the other four never entered the country.