The Japanese government has agreed to sign up to an international treaty that sets procedures for settling cross-border child custody disputes.
Japan is the only one of the Group of Seven industrialised nations yet to join the Hague Convention on International Child Abduction.
Correspondents say the move follows intense foreign pressure on Tokyo.
Its policies have been blamed for making it easy for Japanese mothers to remove children from foreign fathers.
The Hague Convention aims to protect the rights of both parents, and it seeks to ensure that custody decisions are made according to the laws of the country which provided the first residence for the children.
A Japanese official, Yusuke Asakura, said that Prime Minister Naoto Kan's cabinet had endorsed the change.
In Japan, the courts normally give custody to one parent after a marriage breakdown and it is up to that parent whether they let the other parent have any access.
Many separating couples come to amicable agreements, but it is not unusual for one parent to be cut out of their children's lives forever.
There are a quarter of a million divorces in Japan every year, which is relatively low by international standards, but a dramatic increase in its own context.
The BBC's Tokyo correspondent, Roland Buerk, has said that implementation of the decision to follow the Hague Convention is likely to be a long process.
It would mean a change from the expectation that families should largely work things out for themselves, to the state enforcing agreements on access and child-support payments.
Bills to change Japanese law - which has no concept of joint custody - are expected to be submitted to parliament by the end of the year.
But our correspondent says these are likely to face some opposition on the grounds that the changes could hinder Japanese fleeing abusive relationships abroad.
Thousands of Japanese people marry foreigners every year.