Mr. Trump spoke Saturday about the new pressure on Tehran from the presidential retreat in Camp David, where he is spending the weekend discussing Middle East strategy with advisers.

He didn’t provide any further details on the nature of the sanctions…

Mr. Trump also said that Marine Gen. Joe Dunford cautioned him against the plan to strike Iran, which had been drawn up by John Bolton, the president’s national-security adviser.

Asked if Gen. Dunford was advising him against the strikes, Mr. Trump said, “He was.”