President Donald Trump agreed to raise one of Japan's most important political issues with North Korean leader Kim Jong Un.

While meeting with Prime Minister Shinzo Abe, Trump said he would try to resolve the issue of more than a dozen Japanese citizens who were abducted by North Korea in the 1970s.

This is a huge win for Abe, whose support in Japan has plummeted as his country faded into the background on fast-moving talks with North Korea.

But one expert told Business Insider it would be "tragic" if abductees' families put faith in Trump.

In the 1970s, more than a dozen people went missing from coastal areas of Japan, abducted by North Korea in a failed attempt to turn Japanese citizens into spies.

Pyongyang didn't admit to the kidnappings until 2002, when Kim Jong Il, in an attempt to receive aid, returned five abductees to Japan. At the time, North Korea said it abducted only 13 people and the remainder had died — a claim widely doubted in Japan. The abductions, believed to be of 17 people, have remained a hot political issue, particularly as family members of the taken youths grow older.

But at a news conference in Florida on Wednesday with Prime Minister Shinzo Abe, President Donald Trump said the US would bring the cause up with North Korean leader Kim Jong Un directly.

Trump said that during a dinner on Tuesday night, Abe "started talking about abduction and how horrible it was."

"And his level of enthusiasm was unbelievable," Trump continued. "And I said to him right then and there last night at the table, I said we will work very hard on that issue, and we will try and bring those folks back home."

A day earlier, Abe expressed gratefulness that Trump himself would take up the issue at his planned meeting with Kim, and Trump replied, "You have my commitment."

It's a huge win for Abe.

The Japanese prime minister's popularity — and grip on power — had plummeted back home, because of both a political scandal involving his wife and his constant exclusion from the fast-moving talks concerning the country's biggest security threat, North Korea.

In the past, Abe was the world leader closest to Trump, and the two bonded over games of golf as well as a hardline approach to North Korea. In the first 11 months of Trump's presidency the two talked on the phone 13 times — more than Abe and Obama did during Obama's entire second term.

But Abe received no warning about Trump's decision to accept a meeting with Kim and has been scrambling ever since. Japan was even forced to ask China about Kim's meeting with President Xi Jinping after finding out about the visit in the media, long after Beijing had briefed Washington and Seoul.

In meeting with Trump and gaining assurances on the abductions issue — which Abe had made a top policy priority for his administration — the prime minister is most likely feeling more confident about his relationship with Trump and the Japanese people than he had in months.

"Whether Japan will be left behind, that is not at all the case," Abe said at the news conference with Trump. "In the last two days, together with President Trump, we have spoken about North Korea. We have gone into really in-depth discussion. About our policy and direction, we have reached agreement."

This isn't the first time Trump has raised the abductions issue

President Donald Trump and Japanese Prime Minister Shinzo Abe with the US first lady, Melania Trump, and the Japanese first lady, Akie Abe, during a November 6 meeting in Tokyo with families who have had relatives abducted by North Korea. JIM WATSON/AFP/Getty Images

Speaking at the UN last year, Trump mentioned the story of Megumi, who he said was kidnapped at age 13 while playing on the beach and forced to become "a language tutor for North Korea's spies."

He also met the families of the abductees, who were chosen by North Korean commandos mostly at random, while on a tour of Asia in November.

"I think it would be a tremendous signal if Kim Jong Un would send them back," Trump said at the time. "That would be the start of something I think would be just something very special, if they would do that."

And the latest news has again raised the hopes of family members whose siblings, children, and parents were taken more than 40 years ago.

Hope in Trump may be misguided

Trump and Abe at the White House last year. Chip Somodevilla/Getty Images

But hoping Trump raises the issue with Kim, and can even deliver a positive outcome, may be misguided.

In meeting the families of those abducted by North Korea, Trump was following a pattern set by the two presidents before him and most US ambassadors.

Robert S. Boynton, a journalism teacher at New York University who wrote "The Invitation-Only Zone: The True Story of North Korea's Abduction Project," told Business Insider at the time of the meeting last year that little was likely to be achieved.

"The families have become a kind of sacred shrine officials must visit in order to demonstrate that they and their loved ones have not been forgotten," Boynton said. "The Japanese government uses these visits to show that the US cares and hasn't abandoned Japan. It is all theater because most US officials know virtually nothing about the abductions."

"It is tragic if the abductees' families put real faith in Trump," he added. "He couldn't remember the name of a slain US soldier, and I'm sure he's already forgotten about Megumi Yokota."