WASHINGTON—President Trump satisfied briefly on Friday with the Kuwaiti ruler’s son and afterward explained the tiny Gulf Arab state would soon turn out to be the future place to normalize relations with Israel.

Sheikh Nasser Sabah Al-Ahmad Al-Jaber Al-Sabah, the Kuwaiti emir’s eldest son, did not speak to reporters, and the Kuwaiti Embassy in Washington did not instantly respond to a request for comment on Mr. Trump’s assertion.

“They…