Can UK citizen walk into Mexico from US?

No, UK citizens cannot simply walk into Mexico from the US. While Mexico does have a land border with the US, there are formal entry and exit requirements that must be met when crossing between the two countries. This includes presenting a valid passport and, in some cases, obtaining a Mexican visa. Entry requirements may vary depending on the purpose and duration of the intended stay, so it's important to consult the official sources to ensure compliance with current regulations.