Trump posted an image on his social media platform on Tuesday posing with former British Prime Minister Boris Johnson.

"Nice meeting with Former Prime Minister, Boris Johnson, a very fine guy!" Trump posted.

It's not clear if Johnson will be attending RNC events on Tuesday.

Former President Donald Trump campaign's senior adviser Chris LaCivita spoke at a panel hosted by pro-Second Amendment group USCCA on Tuesday morning updating the crowd about Trump's recovery and message of unity.

LaCivita said both Trump and himself are supporters of the Second Amendment and reiterated the former president's messaging has always been to allow law-abiding citizens the ability to carry firearms to protect themselves and their families.

"It's also really important in this election, because Biden has made it clear he wants to ban them," LaCivita said. "There are so many things that you can do to curb the problem of individuals as opposed to trying to ban what is clearly… a right."

-ABC News' Kelsey Walsh, Lalee Ibssa and Soorin Kim

Trump's campaign announced that he and JD Vance will be holding a rally in Grand Rapids, Michigan, on Saturday.

This will mark their first rally together and the first one after Trump's assassination attempt. The rally will take place in an indoor venue.

-ABC News' Lalee Ibssa and Soorin Kim

Merchandise abounds outside of the convention center, with official RNC-branded souvenirs sold inside the Fiserv Forum. The signature red "MAGA" hat is sold at all of them, but all of the vendors have slightly different stock.

A vendor outside of the main security line was selling shirts with the now-iconic photo after the assassination attempt of former President Donald Trump, while another inside of the security perimeter sold T-shirts that declared "I'm voting for the felon."

The official RNC store features T-shirts with Trump's mugshot along with more niche merchandise such as Christmas ornaments.

-ABC News' Diana Paulsen

Pennsylvania Senate hopeful Dave McCormick, who witnessed the assassination attempt on Trump, addressed the "terrifying" moment at the start of his remarks.

"I want to first acknowledge what transpired a few days ago in my home state where I witnessed firsthand from a front-row seat in Butler President Trump's remarkable strength and resolve in a terrifying and unpredictable moment," he said. "The president rose brilliantly to the challenge."

He acknowledged the victims of the incident before saying, "We all thank God President Trump is OK."

On the election, he posited it as a choice between "strength and weakness," between "America's greatness or its sad, disgraceful decline."