LONDON — The British government will put fresh pressure on Tokyo to improve the rights of its citizens seeking access to their children living in Japan with estranged partners.

The effort is to cover Britons who are either seeking the return of their kids to the U.K. or are denied access to their offspring by Japanese courts.

The Foreign Office believes Japanese courts handling custody cases could be breaching obligations under the U.N. Convention on the Rights of the Child. The courts generally side with the Japanese parent and order the children to remain in their care in Japan.