‘A tiny spot that will be gone tonight,’ president says.

President Trump said the Islamic State extremist group would suffer its final territorial defeat by Wednesday evening, even as U.S.-backed fighters in Syria were still completing the battle against the militants. Speaking to reporters before traveling to Ohio, Mr. Trump held up an image of two maps, one depicting how much territory was under Islamic State control on Election Day in 2016, and the second showing the small area that remained as of Wednesday. Pointing to the second map, Mr. Trump said: “In fact, there’s actually a tiny spot that will be gone tonight.” Mr. Trump’s assertion wasn’t confirmed by Pentagon officials, who said that while Islamic State’s defeat was imminent, the formal end of the group’s self-proclaimed caliphate likely is days away, not hours.

Mr. Trump said 400 U.S. troops would remain in the country after Islamic State’s defeat. U.S. defense officials have told The Wall Street Journal that as many as 1,000 troops could remain in the country, a residual presence needed to prevent a resurgence and ensure stability of areas cleared by U.S.-backed local forces. Local ground forces known as the Syrian Democratic Forces have led the anti-Islamic State campaign, with support from a U.S.-led international coalition, which said the pace of combat had slowed Wednesday.

Immediately after Mr. Trump’s remarks, White House officials said they had no announcements to make regarding the state of the campaign. The SDF would likely first announce the defeat of the extremist group, U.S. defense officials have said.

On a Twitter account associated with the SDF, a map was posted Tuesday showing a piece of land still under Islamic State control. But the SDF had not declared the group’s defeat as of Wednesday afternoon.

More From The Wall Street Journal (subscription required):