He promised to “expedite it so people can come back in” after the deportation. “The good people can come back,” he said.

The crimes committed by undocumented immigrants have been a focus of Mr. Trump’s early campaign. He has accused Mexico of sending criminals and rapists to the United States, and has often infuriated Latinos with his remarks.

In his formal policy, as he has many times before, Mr. Trump maintains that “Mexico’s leaders have been taking advantage of the United States by using illegal immigration to export the crime and poverty in their own country.”

Other parts of the plan are similar to the proposals of his rivals in the Republican race. He proposed enforcing the nationwide e-verify system, ending birthright citizenship for the children of illegal immigrants and increasing the prevailing wage for the temporary H-1B visas.

While Mr. Trump spent much of the interview reaffirming his stance on illegal immigrants, at times he struggled to answer questions on other issues.

On foreign policy, Mr. Trump indicated that he was staking out most of his early positions without much outside counsel.

“I watch the shows,” Mr. Trump said when asked whom he talked to for military advice. “I mean, I really see a lot of great — you know, when you watch your show and all of the other shows and you have the generals and you have certain people that you like.” He later added that he was a fan of former Ambassador John R. Bolton and retired Col. Jack Jacobs.