President Trump is sending conflicting messages about his immigration crackdown, promising a reprieve for certain industries that rely on immigrant labor while doubling down on his promise to arrest and deport anyone who is living in the United States illegally.

The situation has left business owners unclear on exactly what the Trump policy is, just days after the president said “changes are coming” to help those in the farming and hospitality industries whose employees are too scared to show up for work.

“One minute you have a message saying they won’t go after agriculture, the next something else,” said Manuel Cunha Jr., president of the Nisei Farmers League, a growers organization in the Central Valley of California.

Mr. Cunha said it was causing “tremendous havoc” in the country’s largest agricultural region.

“First thing this morning I got calls from my growers asking, ‘Does this mean they are going to come after the workers in the fields?’” Mr. Cunha said.

The muddled messages coming out of the White House and from Trump officials suggest the president is caught between competing factions on an issue that has come to define his political identity and that he credited for his victory last year.