MILWAUKEE – The Republican National Convention kicks off on Monday, just two days after former President Donald Trump, the GOP's standard-bearer, survived an assassination attempt.

And the Saturday shooting at Trump's rally in western Pennsylvania - where one spectator was killed and two more critically injured, and the former president visibly bloodied after a bullet grazed his ear - has altered the tone and raised the stakes of the convention.

U.S. Secret Service and other officials announced on the eve of the convention that there are no plans to expand the security perimeter and that there are no known threats.

LIVE UPDATES: REPUBLICAN NATIONAL CONVENTION

"The arena's set, the security is here and we feel very comfortable that we're working with the Secret Service," Republican National Committee chair Michael Whatley said in an interview on "Fox News Sunday."

The Republican National Convention gets underway on Monday with the roll call nomination of former President Trump

The Fiserv Forum in Milwaukee, Wisconsin, on July 14, 2024, on the eve of the start of the Republican National Convention (Fox News - Paul Steinhauser)

Whatley emphasized that "this is going to be a facility where we're going to be able to have 50,000 delegates and alternates and guests and members of the media who are going to be here and who are going to be safe. That's very critical for us."

CLICK HERE FOR THE LATEST FOX NEWS REPORTING FROM THE REPUBLICAN CONVENTION

Trump, in a social media post on Sunday, said that he was going to delay his trip to the convention in the wake of the shooting, but decided against allowing a "potential assassin" to alter his plans.

The former president arrived in Milwaukee, swing state Wisconsin's largest city, a couple of hours later.

Donald Trump arrives on Trump Force One in Milwaukee

Republican presidential candidate and former President Donald Trump arrives on Trump Force One in Milwaukee, Wisconsin, U.S., July 14, 2024 a day after he survived an assassination attempt at a rally in Butler, Pennsylvania.   (REUTERS/Cheney Orr)

At the four-day confab, Trump will formally become the Republican Party's presidential nominee. 

And as the convention gets underway, all eyes are on the former president as Trump's extremely likely to announce his running mate.

The first order of business, as roughly 2,400 Republican delegates from across the country gather at the Fiserv Fourm in downtown Milwaukee, will be officially nominating Trump during a roll call of the states during Monday afternoon's session.

TRUMP CAMPAIGN AND RNC EMPHASIZE CONVENTION TO ‘PROCEED’ IN AFTERMATH OF ASSASSINATION ATTEMPT

Trump is scheduled to accept the nomination as he delivers his address to the convention on Thursday night.

The gathering, which is expected to attract roughly 50,000 attendees, is scheduled to maintain its original programming despite Saturday's shooting. And speakers were asked not to alter their speeches in light of the shooting.

The Trump campaign says that the former president - following his brush with death - at the convention will call for unity in the face of tragedy instead of criticizing his political adversaries.

Senior Trump campaign adviser Jason Miller, in an interview Sunday night on Fox News "Jesse Waters Primetime," said that Trump "was dictating to us some additional things that he wants in his speech as he looks ahead to Thursday. And I think the tone is really going to impress people. He knows that this is a key moment. He's the only one who can step up and lead in this time. And this country is desperate for leadership."

And Trump, in an interview Sunday with the Washington Examiner, said "honestly, it’s going to be a whole different speech now."

"It is a chance to bring the country together. I was given that chance," he emphasized.

Republican presidential candidate former President Donald Trump is rushed offstage

Former President Donald Trump is rushed offstage after shots were fired during a rally on July 13, 2024 in Butler, Pennsylvania. (Anna Moneymaker/Getty Images)

Republicans are aiming to use the convention as a venue to reunite the party and energize delegates and activists ahead of the final stretch of the campaign in Trump's 2024 election rematch with President Biden.

CLICK HERE TO GET THE FOX NEWS APP

As part of that push for unity, Trump's final rival in this year's GOP presidential nomination race will now speak at the convention.

Former South Carolina Gov. Nikki Haley, who served as U.N. ambassador in the Trump administration, will address the convention on Tuesday, a person familiar with the decision confirmed to Fox News on Sunday.

Haley, who was engaged in a bitter two-candidate battle with Trump from late January through early March, when she ended her White House bid, wasn't originally invited to the convention.

Also on tap on Monday as the convention gets under way - A new slimmed-down Republican Party platform that won quick and overwhelming initial approval last week is expected to be passed during the opening session.

While the platform – which softens longstanding Republican Party language in support of a federal ban on abortion – was praised by a number of top social conservative leaders, not all evangelicals were happy with the new document.

Its expected passage is the latest sign of Trump's expanding ideological grip over the GOP.

Get the latest updates from the 2024 campaign trail, exclusive interviews and more at our Fox News Digital election hub.