MEXICO CITY (AP) — A former U.S. Army and CIA officer formally presented his credentials to Mexico’s president Monday as the new United States ambassador to that country at a moment of increased U.S. pressure to fight the drug cartels and delicate trade negotiations.

Amb. Ron Johnson, who served as ambassador to El Salvador during the first administration of U.S. President Donald Trump, met with President Claudia Sheinbaum at the National Palace along with his wife Alina Johnson. He left without making comments to the press.

A U.S. special forces veteran, Johnson formed a close bond with El Salvador President Nayib Bukele, frequently appearing in the president’s social media feed celebrating occasions outside of government functions.

Johnson had been a U.S. military adviser in El Salvador during that country’s civil war in the 1980s and pursued war criminals in the Balkans in the 1990s.

His arrival in Mexico comes in the first year of Sheinbaum’s presidency. She has shown greater willingness to take a harder stance against the country’s powerful drug cartels than her predecessor and an ability to manage the sometimes erratic diplomacy of the Trump administration.

Trump designated several Mexican cartels foreign terrorist organizations this year and U.S. prosecutors announced the first terrorism-related charges against people accused of working with the cartels last week. He has also announced and then suspended most tariffs on imports from Mexico.

Immigration has been at the top of Trump’s agenda, but the flow of migrants across the U.S. border that had already been falling in the final months of the Biden administration has slowed to a comparative trickle.

Sheinbaum also recently announced that Mexico would increase the amount of water it sends to the Rio Grande in an attempt to make up a water debt to Texas farmers.

The deadly wreck of a Mexican Navy tall ship with the Brooklyn Bridge Saturday adds one more binational issue to the relationship. Two sailors died and the incident is under investigation.

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