Trump shooting updates: Shooter flew drone 200 yards from site hours before shooting

In an internal Trump campaign memo sent to staff, and obtained by ABC News, Susie Wiles and Chris LaCivita ask staff to avoid the campaign offices in D.C. and West Palm Beach and say they're enhancing the armed security presence with 24/7 officers on site.

Wiles and LaCivita said the Republican convention will continue as planned and asked staff not to comment publicly on what occurred.

"We condemn all forms of violence, and will not tolerate dangerous rhetoric on social media," they said in the memo.

-ABC News' Katherine Faulders

Former President Donald Trump on Sunday called for Americans to "stand United" after an assassination attempt at his Pennsylvania rally left one person dead.

It was "God alone who prevented the unthinkable from happening," the former president said in a post on the Truth Social platform. Trump previously said he was struck in the ear by a bullet.

Trump added, "In this moment, it is more important than ever that we stand United, and show our True Character as Americans, remaining Strong and Determined, and not allowing Evil to Win."

-ABC News' John Santucci and Kevin Shalvey

Officials on Sunday will be reexamining security plans for the Republican National Convention to determine whether any changes need to be made in light of Saturday’s assassination attempt, a senior federal official told ABC News.

The convention is scheduled to begin Monday in Milwaukee, Wisconsin.

Security details could be altered ahead of the event, including the number of agents and snipers deployed to the locations used by people under U.S. Secret Security protection.

Officials may also decide whether events outside the convention perimeter should be canceled, moved or have enhanced security measures.

-ABC News’ Aaron Katersky, Josh Margolin and Pierre Thomas

Former President Donald Trump's daughter Tiffany said that "political violence is never the answer," as she thanked members of the Secret Service and law enforcement for "fearlessly" intervening on Saturday.

"Please include the families of the victims in your prayers," she said on social platform X. "As you saw today, my father is a fighter and he will continue to fight for you and the USA."

The former president's eldest son, Donald Trump Jr., said in a separate statement on social media that the shooting should "get the same attention" as the attack on the Capitol on Jan. 6, 2021.

-ABC News' Oren Oppenheim and Kevin Shalvey