President Donald Trump is reported to be planning to mark the 25th anniversary of the Sept. 11 attacks at the Pentagon rather than attend the Ground Zero ceremony, but the event is still in the future and the reports describe plans, not a completed or irrevocable decision.
Donald Trump will mark the 25th anniversary of September 11 at the Pentagon without visiting Ground Zero.

Trump Plans to Mark 9/11 at the Pentagon, Not Ground Zero - The New York Times
Source: nytimes.com
Key Evidence
The New York Times reported on Aug. 27 that President Trump planned to mark the 25th anniversary at the Pentagon instead of attending the World Trade Center ceremony in Manhattan.
CNN reported on Aug. 28 that Trump would forego Ground Zero and deliver remarks at the Pentagon, corroborating the reported change in venue.
The sources describe a future plan, not a completed event or a formally documented final schedule, so the claim's certainty is overstated.
What the Evidence Shows
The strongest available reporting supports the substance of the claim. The New York Times reported on Aug. 27 that President Donald Trump was not planning to attend the Manhattan ceremony and instead intended to mark the anniversary at the Pentagon. CNN reporting published Aug. 28 likewise said Trump would forgo Ground Zero and deliver remarks at the Pentagon.nytimes.comnytimes.comTrump Plans to Mark 9/11 at the Pentagon, Not Ground Zero
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Multiple reports attribute the choice in part to the Ground Zero ceremony's longstanding policy against political speeches. The reports say Trump wanted to address an audience and that this preference, along with logistical considerations including travel, influenced the decision. The reason is reported by news organizations and attributed to people familiar with the plans, rather than established by a public White House schedule or formal announcement in the supplied material.mirror.co.ukmirror.co.ukTrump 'to skip 25th anniversary of 9/11 at ground zero in New York because he...
uk.news.yahoo.comuk.news.yahoo.comTrump Planning To Skip The 9/11 25th Anniversary Ceremony At World Trade Center:...+3 more
The wording "will mark" is somewhat stronger than the evidence supports. As of Aug. 28, the Sept. 11 anniversary had not yet occurred, and the sources describe an intention or plan. They do not provide a final presidential schedule, an official White House announcement, or evidence that the Pentagon appearance had already taken place. The claim is therefore supported as a description of the reported plan, but not as a guaranteed final outcome.nytimes.comnytimes.comTrump Plans to Mark 9/11 at the Pentagon, Not Ground Zero
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