Trump Declares ISIS ‘100%’ Defeated. That’s ‘100% Not True,’ Ground Reports Say.

WASHINGTON — President Trump declared on Thursday that “we just took over 100 percent” of territory controlled by the Islamic State in Syria — a claim that reports from the battle front suggested was 100 percent untrue.

“You kept hearing it was 90 percent, 92 percent, the caliphate in Syria. Now it’s 100 percent, we just took over,” Mr. Trump said in remarks to American troops in Alaska. “Now it’s 100 percent, we just took over 100 percent caliphate. That means the area of the land. We just have 100 percent.”

“So that’s good.”

Over the past month, American forces have been working with Syrian fighters to seize the last square mile of Islamic State territory — the riverside village of Baghuz on the border with Iraq. Taking and holding terrain in any military operation can be a difficult task, especially against extremists who are willing to face death instead of surrender.

The battle was continuing on Thursday when officials with the Syrian Democratic Forces, an American-backed militia of Kurdish and Arab fighters, were told of Mr. Trump’s announcement.

“It’s 100 percent not true,” one senior official with the group said on Thursday afternoon. “The fighting continues.”

Separately, a second official said, “The battle is still going, and there is no truth in that statement.”

Both spoke on the condition of anonymity because they were not authorized by their commanders to talk to the press.

Journalists in the area also reported that the Islamic State had not surrendered all of its territory.

“I’ve been in #Syria for the last 28 days covering the offensive and I can assure @realdonaldtrump that is NOT the case,” tweeted Ben Wedeman, a CNN war correspondent.

The Pentagon scrambled to catch up with Mr. Trump’s comments and referred questions to the White House. Although it is true that the Islamic State’s control of territory has dwindled to almost nothing over the last year, Defense Department officials have been wary of declaring victory before the Syrian Democratic Forces seizes Baghuz.

Department officials recently said they were close to declaring an end to the caliphate, but also cautioned that a few hurdles remained. As they take back territory from the Islamic State, the American-backed Syrian fighters must also sweep any buildings for suicide attackers and booby traps that have been left behind — a process that can take days.

On Thursday, Syrian Democratic Forces officials said that fighters were about a week away from declaring victory, with the caveat that the delicate situation could change.

In comments that weaved from Afghanistan to Syria to the advice he receives from his generals, Mr. Trump also said the capture of the Islamic State’s territory happened “in a much shorter period of time than it was supposed to be.”

The president was returning home from a stalled summit meeting in Vietnam with Kim Jong-un, the North Korean leader, but said he could not resist leaving his plane to praise the military during a refueling stop at Joint Base Elmendorf-Richardson in Anchorage.

Trump administration officials have been moving closer to publicly declaring a total rout of the Islamic State from the land it controls. Two weeks ago, Vice President Mike Pence said at the Munich Security Conference that “we have one mile of territory left to capture.”

He added, “Literally within hours or days, the ISIS caliphate will be no more.”

At the same time, the Trump administration has sent mixed messages about the resources it will commit to defeat the Islamic State in Syria. In December, Mr. Trump announced that he would withdraw all 2,000 American troops from Syria. He has since softened that to allow about 400 troops to remain, half as part of a multinational force dedicated to securing the country’s northeast — an area that is vulnerable to the Islamic State.

The Pentagon also wants to keep working with the Syrian Democratic Forces, who have borne the bulk of the fight against the Islamic State.

The White House did not immediately respond to a request for clarification.