Of course. Yes. Both you and your Mexican partner are the parents with full rights, wherever the child happens to be and whatever your nationality may be.Note in Mexico, the mother (regardless of nationality) is usually assumed to be primary caretaker unless she has been proven to be a threat to the children or physically/mentally unfit, or when the child is able to express wishes otherwise and is mature enough to understand the consequences of their decision.Not just that - it is a crime in Mexico for one parent to take their child to live in another state or country without express authorization from the other parent or a judge.Other than that, itu2019s a Western legal system which should be fairly easy to recognize in the US. Child support, alimony, etcetera.Your child also qualifies for dual citizenship and can acquire the other nationality. You can inquire at the embassy or consulate of the country the baby was not registered as a national (usually the country he/she wasnu2019t born in).Your kid is also protected by a bevy of Mexican laws as well as all international rights of the child treaties (Mexico is a signatory to all of them), and as a parent you have full rights to oversee that protection (along with your Mexican coparent, but even if the other party was not present this would be the case).And Mexico has an independent government entity called u201cDIFu201d, which stands for u201cNational System for Integral Family Developmentu201d, which is an institution to help people with most anything regarding families, including family planning, childcare and special needs care, elder assistance, drug abuse prevention or help for people needing temporary assistance, womenu2019s shelters, orphan care and adoptions, etcetera.An overview (from the US standpoint) of the Mexican law with regards to children can be found at Law Library of Congress.And a pretty good primer on Mexican family law (including divorce, common law marriage - usually defined as any couple living together over two years - and child custody (with a focus on Quintana Roo, given the location of the writers) can be found at Common Questions About Mexican Family Law - MexLaw Mexican Law Firm.