Russian and American officials are holding talks in Moscow about United States citizens adopting Russian orphans.
Russia says it will not allow any more adoptions until a treaty is signed.
Earlier this month, an orphan boy, aged seven, was sent back to Russia unaccompanied from the US.
He arrived at Moscow airport carrying a note from a woman in Tennessee who was supposed to be his new mother, saying she did not want him.
The Russian government described the case as "a monstrous deed" and "the last straw".
The BBC reports officials say negotiations for a new treaty could take anything up to six months to complete.
