As he continues to face a backlash for calling President Obama and Hillary Clinton the “founders of ISIS,” Donald J. Trump will travel to the battleground state of Ohio on Monday to discuss his plans to fight terrorism and shore up national security.

The address at Youngstown State University comes as Mr. Trump tries to pivot to serious policy issues from multiple contentious statements.

On Sunday, Trump campaign aides previewed his planned speech in a 40-minute conference call with reporters, saying that it would use the Cold War era as a model for the type of ideological fight the United States is waging against the Islamic State. The New York Times was not invited to join, but it was provided with the number and listened to the call.

Jason Miller, a campaign spokesman, said that Mr. Trump would lay out “three pillars” to fighting radical Islamic terrorism. The speech, Stephen Miller, Mr. Trump’s policy adviser, said, would call for a stricter immigration questionnaire for people from nations with ties to terrorism; for new alliances with nations willing to help fight terrorism; and for a move from “nation-building” to foreign policy “realism.” The questionnaire, he added, would require applicants to prove commitment to the ideals of “tolerance” and “pluralism,” but he did not say precisely how such a thing would be enforced.