Japan gave final approval Friday to an international treaty on how to settle cross-border disputes over the custody of children, officials said.
The cabinet of Prime Minister Shinzo Abe endorsed a decision by both houses of parliament last year to sign the 1980 Hague Convention on the Civil Aspects of International Child Abduction.
The convention will take effect in Japan on April 1, the foreign ministry said.
"Since the number of people who move across borders has dramatically increased and international marriage and international divorce have increased in recent years, it is very important for the Government of Japan to conclude the Hague Convention, which is an international rule to deal with issues such as the wrongful removal of a child," the ministry said in a statement.
The move comes after decades of pressure from the United States and other Western nations.
Japan is the only member of the Group of Eight major industrialised nations that has not joined the Hague Convention, which requires nations to return snatched children to the countries where they usually reside.
Japanese courts virtually never grant custody to foreign parents or to fathers, leaving few legal avenues for those whose former partners have fled to Japan with their children.
Hundreds of U.S. parents have complained that they have no recourse to see their half-Japanese children. At least 120 have filed cases in Japan, invariably to no avail.
U.S. lawmakers have long demanded Japan fall into line on the issue, one of the few open disputes between the close allies.
In February last year, Abe promised action after White House talks with U.S. President Barack Obama.
The law will, however, allow a parent to refuse to return a child if abuse or domestic violence is feared, a provision which campaigners say is vital, but which some say risks being exploited.© (c) 2014 AFP