MEXICO CITY, Oct 6, 2023 (BSS/AFP) - The United States and Mexico pledged Thursday to step up efforts to tackle flows of drugs and migrants, setting aside signs of friction over a US plan to extend a controversial border wall.

Mexican President Andres Manuel Lopez Obrador criticized the announcement by Washington that it would add to the barrier that was a signature policy of Donald Trump, calling it a "setback."

"It does not solve the problem. We must address the causes" of migration, he told reporters shortly before meeting Secretary of State Antony Blinken at the National Palace.

Blinken was accompanied by a delegation including Homeland Security Secretary Alejandro Mayorkas and Attorney General Merrick Garland for the high-level security talks.

The synthetic opioid fentanyl "continues to devastate families on both sides of the border," Blinken said at a news conference afterward.

"We have an obligation to do everything in our power to combat this scourge," he said, adding that the two countries were cooperating to "dismantle clandestine drug labs."

Mexican Foreign Minister Alicia Barcena stressed that the chemical precursors used to make fentanyl were not produced in Mexico but came from abroad.

The Mexican Navy had proposed creating an international coalition to stop chemical precursor smuggling through measures such as improved traceability, she said.

On migration, Blinken said the scale of the challenge "demands that we redouble our efforts" through measures such as modernizing border security, increasing legal migration pathways and addressing the root causes.

Mayorkas said the two countries were committed to expanding "safe, orderly and lawful pathways for migrants" but with "strict consequences" for those who do not use lawful means to enter the United States.

"Those consequences include swift repatriation, the swift return of migrants and a ban on their re-entry," he said.

With US President Joe Biden under pressure to halt border crossings as he seeks reelection, Washington announced Thursday that it would resume deportation flights to Venezuela after a deal with Caracas.

- 'Deadliest drug threat' -

The United States saw a record of around 110,000 drug overdose deaths between March 2022 and March 2023, according to the Centers for Disease Control and Prevention (CDC). Fentanyl accounted for some two-thirds of them.

Garland said the two countries were "taking on the dangerous drug trafficking cartels that are responsible for the deaths of both American and Mexican citizens.

"The fentanyl these cartels are producing and trafficking is the deadliest drug threat the United States has ever faced," he added.

Last month Mexico extradited Ovidio Guzman Lopez, the son of imprisoned Sinaloa Cartel kingpin Joaquin "El Chapo" Guzman, to the United States to face narcotics charges.

"He is one of more than a dozen cartel leaders we have indicted and who have been extradited to the United States. He will not be the last," Garland said.

The US Justice Department is pursuing three more of Guzman's sons, known as the "Chapitos."

US authorities are also targeting Chinese companies accused of cartel links. This week they announced sanctions on a China-based network accused of producing and distributing precursor chemicals.

Mexico is plagued by cartel-related bloodshed that has seen more than 420,000 people murdered since the government deployed the military in the war on drugs in 2006.

Lopez Obrador argues that investing in development projects in the region would help counter not only drug trafficking but also migration flows.

He has angrily rejected calls by Republican politicians in the United States to send the US military to fight drug cartels.