Mexico will wait and see if U.S. President Donald Trump goes through with his threat to slap tariffs on its southern neighbor on Tuesday, the nation's president said on Monday, adding that Mexico has back-up plans in case the tariffs go into place.

WASHINGTON (AP) — President Donald Trump’s long-threatened tariffs against Canada and Mexico finally went into effect Tuesday, putting global markets on edge and setting up costly retaliations by the United States’ North American allies.