"Right now you have a president that talks down to people, talks past them, demoralizing folks living here and their relatives in the United States," Newsom told reporters to close out the first day of his trip. "I think it's important to let folks know that's not our country — that's an individual in our country who happens at this moment to be president."
Newsom, a Democrat who took office in January, chose El Salvador as his first international trip because California is home to both the United States' largest Salvadoran population and its busiest border crossing.
His visit comes as Trump moves to cut millions of dollars in U.S. aid to El Salvador, Honduras and Guatemala and demands those three nations and Mexico do more to stop migrants from entering the United States.
There has been a surge of immigrants seeking asylum from the Central American nations. About 3,000 unaccompanied children and 12,000 family members from El Salvador have arrived at the U.S.-Mexico border since October.
Newsom kicked off his trip with a visit to the tomb of Saint Oscar Romero, the Salvadoran priest assassinated in 1980 at the start of the nation's civil war because of his advocacy for human rights and the poor.
The visit served as a symbol of Newsom's desire to learn about the social and economic hardships forcing Salvadorans to leave. After a private tour of the cathedral where Romero preached, Newsom lit a candle near Romero's tomb in the cathedral basement alongside his wife, Jennifer Siebel Newsom, and California state Assemblywoman Wendy Carrillo.
Newsom's trip includes meetings with President Salvador Sanchez Ceren, U.S. Ambassador Jean Manes and President-elect Nayib Bukele. He'll also tour a reintegration center that processes Salvadorans deported from the United States and Mexico, see a cultural demonstration in a rural town, meet with human rights groups and discuss economic development and gang intervention.
Newsom said he's figuring out in real time what more California can do to help tackle the root causes of migration, namely deep poverty and gang violence. El Salvador is one of the world's most violent countries, with the gangs MS-13 and Barrio 18 exerting strong control. The minimum wage is just $300 per month.
Mayor Ernesto Muyshondt of San Salvador, the capital city, said he hopes Newsom can use his political influence to halt the cuts to U.S. aid, saying cuts will halt the countries progress and could cause more people to flee.
In Newsom's first three months in office, he has fought the Trump administration on perhaps no issue as much as immigration, suing over the president's emergency declaration to build a southern border wall and pledging $25 million in state money to help asylum seekers.
The Trump administration has not commented on Newsom's trip, but Republicans in California have said the governor should be more focused on poverty back home.
"The tragic circumstances that drive migrants from their homes should remind us that we have people living in crushing poverty in our own communities. Our attention and resources should be focused there," Republican state Assemblyman Devon Mathis said in a statement.
Newsom pushed back on critics, saying immigration is a driving political and policy issue that affects California more than any other state.
"How do you understand California without understanding all the diverse cultures that make it the most diverse state?" he said. "It's fundamental it seems to me to governing a state. That's why I'm here in the first months."
While Newsom hopes to plant a counter-narrative to Trump, he is barely known in El Salvador, a country just over 6 million people.
Before Newsom's visit to the cathedral, people milled about on the Gerardo Barrios Plaza, a public square out front. Only one of a half dozen people who spoke with The Associated Press said they were aware the governor of California was coming to visit, and none knew his name.
Manuel Lara, 52, has family living in Los Angeles and said he learned of Newsom's trip from the news. Lara tried to come to the United States unsuccessfully in the 1980s and now works in construction in El Salvador. He makes $10 per day.
He said Newsom's trip was a good thing given Trump's threats to rescind aid.
Lidia Rosales said she is out of work because there are not enough jobs for teachers. Even if there were, the $125 monthly pay teachers make is not enough to live comfortably, she said. She said she doesn't like how Trump talks about Latinos. But she had not heard of Newsom or why he was visiting.
Newsom said starting the trip at Romero's tomb was an event that brought full circle some of his earliest political awakenings and Catholic upbringing.
"I never thought I'd be kneeling in front of Saint Romero as governor of California," he said.
This story has been corrected to say that President Donald Trump is cutting millions in U.S. aid to El Salvador, Honduras and Guatemala