Britain said on Sunday it would tighten up adoption laws to protect children who are brought in from abroad.
The move, confirmed by the Department of Health, has been prompted by a transatlantic tug-of-war over twins adopted on the Internet by a British couple.
Under new laws to be rushed through parliament, it will become a criminal offence, punishable by up to three months in prison, to bring children adopted overseas into the country without the approval of British authorities.
"Children who are adopted abroad must have the same safeguards as those adopted in this country," a government spokesman said.
Six-month-old Kimberley and Belinda are being fought over by Alan and Judith Kilshaw, who took them to Britain from the United States, natural mother Tranda Wecker of St Louis, Missouri, and a Californian couple who allege they had adopted the girls.
British authorities, concerned about the media circus that has sprung up around the twins, have taken them into protective custody.
Keith McDonough, director of education and children's services for the north Wales region where the Kilshaws live, said proceedings to make them wards of court would be heard in the High Court on Tuesday.
The Kilshaws have vowed to fight for the children but in the meantime the babies remain in the care of social workers.
Senior government ministers have made no secret of their distaste at the saga. Prime Minister Tony Blair said the sale of children via the Internet was "deplorable". Home Secretary Jack Straw said it was "revolting".
Sunday newspapers quoted Health Secretary Alan Milburn as saying adoption was intended to provide better lives for children, not as a service for adults. The government is already in the process of shaking up the adoptions system.
"We want more children to be adopted. It is why we are reforming the system to make it fairer and faster. In doing so, the interests of the child will always come first," Milburn said.