DeSantis is set to make his announcement at 6:00 p.m. Eastern Time on Wednesday during a live audio discussion with Tesla CEO Elon Musk on Twitter.
Late Tuesday, the Florida governor retweeted a 30-second ad that appeared to show him walking on stage to a cheering crowd as an American flag is seen hanging in the distance.Casey, DeSantis' wife, initially shared the video with the caption: "America is worth the fight... Every. Single. Time."
The 44-year-old DeSantis has served as governor of the state of Florida since January 2019, but recently emerged as former President Donald Trump's top challenger for the Republican ticket to the White House in 2024.
However, according to political analysis website Real Clear Politics, Trump holds a 37-point lead over DeSantis among Republican voters as of Tuesday evening.
The Trump camp was quick to react to the Tuesday news, with a spokesperson telling US media a Twitter announcement was "perfect" for DeSantis since "he doesn't have to interact with people and the media can't ask him any questions."
DeSantis is expected to appears on Fox News after the Twitter event.
Earlier this year, DeSantis went on a world tour to boost his foreign policy credentials, visiting US allied states such as Israel, Japan, South Korea and the United Kingdom.
DeSantis served in the US Navy from 2004 to 2019 as a prosecutor, which included brief stints in Iraq and Guantanamo Bay, Cuba. He also served as a legal adviser to SEAL Team 1.