WASHINGTON — President Trump’s first budget offers up dramatic policy shifts and hundreds of millions of dollars to clamp down on undocumented immigrants living in the United States, denying them tax credits, jobs and haven while funding a deportation force and flights home for those being removed.

The proposals, part of the $4.1 trillion blueprint the White House released Tuesday, offer the clearest indication yet of how Mr. Trump, who campaigned on a promise to build a southern border wall to keep immigrants from illegally entering the United States and hunt down and banish those who are already here, intends to carry out his crackdown. In a budget marked by steep cuts to social safety net programs, it is one of the few areas besides the military where the president proposes to increase funding.

“In these dangerous times, our increased attention to public safety and national security sends a clear message to the world — a message of American strength and resolve,” Mr. Trump said in the message accompanying the document. “It follows through on my promise to focus on keeping Americans safe, keeping terrorists out of our nation, and putting violent offenders behind bars.”

To carry out the changes, Mr. Trump has requested a $2.7 billion increase for border security and immigration enforcement, part of a nearly 7 percent increase for the Department of Homeland Security. But his targeting of immigrants reaches beyond spending freely to track and deport them.