The issue focused on an issue of whether the United States should accept refugees coming from Syria.

Mr. Trump had been critical of the U.S. response during the election when the nation was overwhelmed by the surge of Syrian refugees, including some who had been admitted from countries with lax screening procedures.

"When will our country start moving on radical Islamic terrorism, not just at the border, but also online?" he had said. "When will our country be able to identify the security vulnerabilities of our