Japan's Prime Minister Fumio Kishida pledged Tuesday to carry out slain former leader Shinzo Abe's mission of bringing about the return of Japanese abductees by North Korea, but the goal is unlikely to be achieved anytime soon.

Abe's signature "maximum pressure" policy against North Korea made leader Kim Jong Un more reluctant to interact with Japan, eventually depriving Tokyo of an opportunity to hold talks with Pyongyang over the long-standing abduction issue, observers said.

In a memorial address at a state funeral for Abe, who was fatally shot during an election campaign in July, Kishida said he will "do everything in my power" to realize the return of Japanese nationals abducted by North Korea in the 1970s and 1980s.

Japanese Prime Minister Fumio Kishida offers flowers at the state funeral of slain former Japanese Prime Minister Shinzo Abe at the Nippon Budokan hall in Tokyo on Sept. 27, 2022. (Pool photo) (Kyodo) ==Kyodo

Former Prime Minister Yoshihide Suga, known as Abe's right-hand man, also touted his ambition to resolve the abduction issue.

Abe took a hard-line posture against North Korea since he became prime minister in 2012 following his first one-year stint in the post between 2006 and 2007, saying that tackling the issue was his "life's work."

In September 2002, Abe accompanied then Prime Minister Junichiro Koizumi to Pyongyang as a deputy chief Cabinet secretary and asked him to take a tough stance to draw words of apology for the abductions from North Korea's then leader, Kim Jong Il.

After Koizumi signed a historic declaration with Kim Jong Il, five abductees were brought back to Japan, while Tokyo has been seeking the return of 12 others whom it has officially recognized as having been abducted by Pyongyang.

With negotiations at a standstill between Tokyo and Pyongyang, Abe staged a comeback as Japan's top political leader.

In May 2014, the Japanese government reached an accord with North Korea on principles for talks toward the settlement of the abduction issue. Tokyo relaxed its sanctions on Pyongyang, which in turn promised a full-scale investigation into it.

Kishida was foreign minister and Suga was chief Cabinet secretary at that time under the Abe administration.

But North Korea repeatedly delayed reporting the survey results. The nation then disbanded its investigation team and suspended the probe after Japan levied further sanctions in February 2016 in reaction to Pyongyang's nuclear and missile tests.

File photo taken Sept. 17, 2002, shows Japanese Prime Minister Junichiro Koizumi (L) and North Korean leader Kim Jong Il shaking hands in Pyongyang after signing the Pyongyang Declaration. (Kyodo) ==Kyodo

Since then, Abe, Japan's longest-serving prime minister, had intensified a maximum pressure campaign against North Korea to gain concessions, but the policy had "no strategy" to compel Pyongyang to change its course, a diplomatic source said.

In November 2017, Abe endorsed then U.S. President Donald Trump's determination to take military action against North Korea if necessary, triggering opposition from the families of the abductees.

Kaoru Hasuike, who was abducted by North Korea and returned to Japan, urged Abe's government to find a solution to the abduction issue by implementing appeasement measures such as offering food support to Pyongyang.

Abe "did not clearly envision when and how Japan would ease pressure on North Korea. The maximum pressure policy only irritated Kim Jong Un," the source said.

After the first-ever U.S.-North Korea summit in June 2018, Abe reversed the maximum pressure campaign and began to voice eagerness to hold a meeting with leader Kim Jong Un "without conditions."

Abe also sought cooperation from Trump in resolving the abduction issue, while cultivating a personal rapport with him.

Sakie Yokota (far L), whose daughter Megumi was abducted at the age of 13 in 1977, and other family members of victims of North Korean abductions hold a press conference after meeting with U.S. President Joe Biden in Tokyo on May 23, 2022. (Kyodo)

North Korea, however, has shown no signs of holding a summit with Japan, while insisting that the abduction issue has been "already resolved." Abe stepped down as premier in 2020.

As negotiations between Washington and Pyongyang over denuclearization and sanctions relief have been stalled for around three years, Kim Jong Un has been apparently getting closer to China and Russia -- traditionally friendly countries of North Korea.

Japan and North Korea have no diplomatic relations. It is "extremely difficult" for Tokyo to regain a chance to restart talks with Pyongyang on the abduction issue, said the source from a nation that has diplomatic ties with North Korea.

Abe claimed that Japan would make efforts to settle several matters, including the abduction issue, before normalizing relations with North Korea based on the "Pyongyang Declaration," which the then leaders of the two countries agreed on in 2002.

"I don't know why Japan has not tried to solve the abduction issue after normalizing ties" with North Korea, the source said. "If the Japanese government does not change its policy, mostly hammered out by Abe, it cannot break down the status quo."