US President Barack Obama has added Belize and El Salvador to a blacklist of countries considered major producers or transit routes for illegal drugs. The blacklisting came on the day El Salvador celebrates independence from Spain and days before Belize also observes its Independence Day.
Officials said cartels were using the two Central American nations as routes for smuggling cocaine from South America north to Mexico and the US. In total, 22 countries were included on the drugs blacklist.
Three were deemed to have "failed demonstrably" in the fight against drugs - Burma, Bolivia and Venezuela. Correspondents say the inclusion of Belize and El Salvador on the list reflects the growing influence of Mexico's powerful drugs cartels.
In El Salvador in particular, the Mexican cartels are thought to be forming alliances with street gangs known as "Maras". On a visit to El Salvador last March, President Obama promised $200m (£139m) to help fight crime in Central America.
Further international aid was promised at a regional security conference in June, amid concerns that small Central American states lack the resources to stand up to Mexico's drugs cartels.
About two-thirds of the cocaine entering the US is thought to pass through Central America, and the region also has some of the highest murder rates in the world.
The other Central American countries - Costa Rica, Guatemala, Honduras, Nicaragua and Panama - were already on the blacklist, as were Mexico and major cocaine producers Colombia and Peru.
The US president is required to notify Congress each year of major drug producing and transit nations.