FIRST ON FOX: A Republican congressman has personally delivered a letter to Japan’s prime minister urging him to take action in order to address the issue of hundreds of American children being abducted and held in Japan by parents who took the children from the other parent without their consent.

"As our two countries continue to take steps to strengthen our democratic, economic and security ties, I would like to draw your attention to an open wound that threatens to derail many ongoing efforts," GOP Rep. Chris Smith wrote in a letter that he hand-delivered to Japanese Prime Minister Fumio Kishida.

"To date, more than 500 American children have been abducted to Japan by one of their respective parents and remain separated from their American parent. These abductions often occur against pre-existing court orders and, in some cases, with the passport assistance of the Japanese government."

Japanese Prime Minister Fumio Kishida, left, and Rep. Chris Smith. ( )

"For the sake of the children who are suffering, and for the sake of U.S. and Japanese relations, I seek your public commitment to reunite these families," Smith wrote in the letter. "I respectfully request that you work with the United States to create a process by which families can be reunited and heal."

Smith points out in his letter that the House of Representatives passed H. Res. 1326 in 2010 calling on Japan to "address the urgent problem of abduction to and retention of United States citizen children" and in 2014, the Sean and David Goldman International Child Abduction Prevention and Return Act was signed into law to "prevent the terrible crime of international parental child abduction and empower the U.S. executive branch with tools to address this problem bilaterally with countries of particular concern."

"Regrettably, the abduction of American children to your country remains an ongoing human rights crisis that cannot be sidelined or overlooked," Smith wrote. "When a country such as Japan has failed to resolve 30 percent of abduction cases that have been pending more than 12 months, U.S. law requires the Secretary of State to take action."

Smith wrote that the Goldman Act has helped return U.S. citizen children from other countries but "Japan has not assisted in any notable returns."

Japanese Prime Minister Fumio Kishida speaks during a news conference in the Rose Garden of the White House on April 10, 2024. (AP Photo/Alex Brandon, File)

Smith wrote in his letter that the National Center for Missing and Exploited Children has found that abduction victims are often taught by their kidnapper that the left-behind parent "doesn't want them" or that the left-behind parent is "dangerous," "harmful," "dead" or "unknown."

"This trauma is not easily erased," Smith wrote.

Unlike many other countries, Japan does not allow dual custody of children for their divorced parents. Only one parent can take the children, though the other parent can gain visitation rights. In some cases, the parent with custody blocks contact with the other one.

There have been some high-profile cases of custody disputes brought up by foreign husbands divorced from Japanese women accusing them of child abduction.

"Your Excellency, it is my sincere hope that these Japanese American children will become a source of strength between our two countries rather than a reminder of an ongoing injustice and a barrier to a robust United States-Japan relationship," Smith concluded in his letter. 

"I respectfully request that you work with the United States to create a process by which families can be reunited and heal."

President Biden, left, and Japanese Prime Minister Fumio Kishida toast during an official State Dinner at the White House in Washington, D.C., April 10, 2024. (REUTERS/Evelyn Hockstein)

In a statement to Fox News Digital, Japan's Ministry of Foreign Affairs said, "Since the Convention on the Civil Aspects of International Child Abduction (the so-called "Hague Convention") entered into force in Japan in 2014, Japan has been taking appropriate measures to deal with cases covered by the Hague Convention through cooperation with each contracting state based on the Convention."

"Regarding cross-border child abduction cases between Japan and the U.S., the relevant authorities in both countries cooperate to appropriately respond to such cases."

The statement continued, "The Government of Japan has explained the position of the Government of Japan, including the above points, to relevant U.S. officials, including Congressman Smith."

Fox News Digital's Matthew Noyes and The Associated Press contributed to this report.