Relations between the United States and its southern neighbour are growing increasingly strained over President Donald Trump's pledge to move quickly on a border wall with Mexico.
Now, Mexico City has become the focus of mass protests across the country.
Activist Maria Amparo Cassar says the new US president is a threat to not just Mexico, but the world.
"Mr Trump has taken Mexico and the Mexican community in the United States as his preferred target for the policies that he has taken internationally. It's a threat to the global community. It should not be forgotten that American society was made by migrants and continues to be made by migrants, and so these policies of Mr Trump's run counter to these principles, against plurality."
Reports of immigration sweeps this week sparked fears of mass deportations from the United States.
And those reports follow a pledge by Mr Trump to make Mexico pay for a border wall and a push to renegotiate trade agreements, which could harm the country's economy.
Protester Francisco Rivas says it is crucial that relations between the two neighbours are not allowed to deteriorate further.
"With the United States, we need to resolve whatever difference we have, because we will not be able to move the country forward. So it is best to work together and to strengthen a relationship that is mutually beneficial. But the current government of the United States has declared it an enemy of Mexico."
There were protests, too, in New York.
"'No, you can't. No, you can't.' Chant with me. 'No, you can't. No, you can't. No, you can't.'"
Calling for community unity, the city's mayor, Bill De Blasio, quoted from a German pastor at the time of the World War Two Nazi holocaust.
"First, they came for the socialists, and I did not speak out, because I was not a socialist. Then they came for the trade unionists, and I did not speak up, because I was not a trade unionist. Then they came for the Jews, and I did not speak out, because I was not a Jew. And then they came for me, and there was no-one left to speak out for me."
New York City comptroller Scott Stringer says the Jewish community knows too well the dangers of the administration's stance on refugees and migrants.
"At a different time and in a different era, our people, grandparents and great-grandparents, were turned away from this country. And we who are here today, the sons and daughters of a previous generation, we say to our refugees, we say, 'Come one, come all.' And we say to Donald Trump, 'Get out of the way!'"
The President has taken to Twitter to defend his policies.
He says the crackdown on what he calls "illegal criminals" is merely in keeping with his campaign promise.
He says gang members, drug dealers and others are being removed.