Mexican authorities have made what they say is one of their largest drug seizures after finding 23.5 tons of cocaine at the port of Manzanillo.
The cocaine was found in more than 21,000 individual packages
The drugs, with an estimated street value of more than $400m (£192m), were found in by the Mexican navy in cargo containers on a ship from Colombia.
The seizure dwarfed the 11.5 tons found last month at the port of Tampico.
The US ambassador said the seizures showed Congress should approve funding for a major new anti-drug initiative.
"This seizure highlights the need for US Congressional action on the proposed Merida Initiative, which will provide both countries with more and better tools to co-ordinate our high-stakes battle against the cartels and their narco-trafficking activities," Antonio Garza Jr said in a statement.
Mr Garza also said the seizure was "further proof of President [Felipe] Calderon's commitment to cripple drug lords and bring them to justice".
The Mexican attorney-general's office initially said on Tuesday that the navy had discovered 11 tons of cocaine onboard the ship Esmeralda, which had arrived from Buenaventura in Colombia.
But on Thursday, the navy announced it had found a second stash of cocaine amid the ship's cargo, bringing the total seizure to 23.5 tons.
The navy said the cocaine was found in more than 21,000 packages and that the final tally could rise further because officials had not yet finished searching all of the ship's containers.
"With actions such as this one, the Mexican government reaffirms the reach of the strategy being executed by this administration to break the operational networks and the business of organised crime groups dedicated to damaging the health, security and well-being of Mexican society," Public Security Minister Genaro Garcia Luna said in a statement.