MEXICO CITY — A group of Latin American leaders declared Monday that votes by two U.S. states to legalize marijuana have important implications for efforts to quash drug smuggling, offering the first government reaction from a region increasingly frustrated with the U.S.-backed war on drugs.

The declaration by the leaders of Mexico, Belize, Honduras and Costa Rica did not explicitly say they were considering weakening their governments’ efforts against marijuana smuggling, but it strongly implied the votes last week in Colorado and Washington would make enforcement of marijuana bans more difficult.