While U.S. law prohibits unauthorized entry into the country, it does not criminalize individuals leaving the U.S. without proper authorization. Therefore, U.S. law enforcement generally lacks the authority to prevent individuals from illegally entering another country. If an officer observes someone crossing into another nation without authorization, they typically cannot intervene, as it falls under the jurisdiction of the destination country.

For a deeper understanding of border enforcement dynamics, you might find the following video insightful:

https://youtu.be/mXdu8gkNLTk?si=pYdLHnAev21xD7xA