You should note that when international politics and diplomacy are involved, there are no real friends but different countries with common or diverging interests that more often than not, end up in 'friendly rivalries', contempt or even outright war.
Right now, Mexico is a close business and trade partner of the United States, Guatemala and Belize (its neighboring countries). It however, has an uneasy relationship with both Guatemala and the United States, being the main reason the large influx of illegal immigrants from Guatemala to Mexico, and from Mexico into the United States. Also drug and weapons trafficking along the three countries' borders further complicate their relationship.
Canada and Mexico are neighboring countries of the United States.
If you mean states as in countries, then Canada and Mexico.
The "neignboring countries" of the US are Canada (north) and Mexico (south). The US state of Alaska has a sea border with Russia (Bering Strait) and the US state of Florida has a sea border with the Bahamas to the east and Cuba to the south.
America does not have direct neighboring countries. However, the United States shares borders with Canada to the north and Mexico to the south.
Mexico and Canada
The US president undoubtedly has some effect on much of the world and more especially on neighboring countries like Mexico. Exactly what effect he has is hard to say and varies with time.
Mexico does NOT have nuclear weapons. Its of no use to us. Mexico has what many countries crave, no problems with other countries, so much so, that Mexico's military isn't trained for war, its just trained for defense inside the county. If Mexico began to produce nuclear weapons, it would mean a large split in US-Mexican relations, and Mexican-World relations.
As a close neighboring country to the US, they shared the benefits of US industrialization.
Bermuda is a British territory in the Atlantic. It has no bordering countries. The closest countries to Bermuda are the US and the Bahamas.
The main countries that border the US are Canada, and Mexico.
Canada and Mexico.
Mexico and Canada.