Donald J. Trump on Tuesday abruptly canceled a news conference that he had scheduled at his Mar-a-Lago resort for Thursday evening on the one-year anniversary of the breaching of the United States Capitol.

Mr. Trump’s initial decision on Dec. 30 to counterprogram the remembrance events to be held on Capitol Hill had drawn immediate concern from Republicans and allies, who questioned the wisdom of his seizing the spotlight for himself, saying it would be a needless and harmful distraction.

Republicans, including Mr. Trump in a statement on Tuesday, have tried to divert attention from the fact that it was the former president’s supporters who turned violent as they sought to stall the certification of the 2020 election, and to falsely blame House Speaker Nancy Pelosi for the rioting.

Mr. Trump’s encouraging speech to supporters on Jan. 6, delivered shortly before the riot, was the centerpiece of his second impeachment by the Democratic-led House of Representatives. He was acquitted by the Senate when it failed to reach a two-thirds majority to convict him of “incitement of insurrection.”

In his statement, Mr. Trump faulted both the media and the ongoing House investigation into the assault on the Capitol for his cancellation, but said he would “discuss many of those important topics” at a rally he is planning for Jan. 15 in Arizona.

In recent days, according to people familiar with the matter, it became clear that Mr. Trump’s news conference would not likely receive the kind of blanket cable coverage that he generally desires, and some advisers urged the former president to reschedule for a day that would draw less attention to a low point of his presidency.

Both President Biden and Vice President Kamala Harris are scheduled to speak on Thursday, and Speaker Pelosi told lawmakers in a letter last week that there would be a full day of events, including a prayer vigil on the Capitol steps in the early evening.

“These events are intended as an observance of reflection, remembrance and recommitment, in a spirit of unity, patriotism and prayerfulness,” she wrote.

Maggie Haberman contributed reporting.