As reported elsewhere, White was briefed on the news on Monday evening.
The 23-year-old is said to be surprised but delighted with the inclusion and hopes to make his way into the final 26-man squad.
Southgate will officially name their provisional squad at 1 p.m. Tuesday before giving a press conference at 2 p.m. – the England manager is then due to submit his final squad by June 1.
White, a versatile player who has played in defensive midfielder and right-wing roles as well as center-back this season, has yet to represent England at any level.
He has started 36 Premier League games this season and Southgate was in the stands to watch Brighton’s 1-1 draw with West Ham earlier this month.
“He was exceptional. I described it as a Rolls Royce. He moved as eloquently as a footballer can. I think he will play at the highest level and I think he will represent England. “
White is a Brighton Academy graduate and was loaned out to Newport County, Peterborough United and most recently Leeds United in 2019-2020.
For a profile of young Premier League stars earlier this year, White was described as a ‘Rolls Royce’ of a defender by Newport manager Michael Flynn, who tipped the player for a callback from the England.
Flynn a dit Sky Sports News: “I knew he was going to become a shining star just by looking at him day after day. When he goes to play the performances he did against Leeds and Tottenham then you start to realize how great he can be.
“He was exceptional. I described it as a Rolls Royce. He moved as eloquently as a footballer can. He was faster than he looked, he read the game exceptionally well for someone of that age, and he was a big boy across the board. His demeanor was first class.
“For me my biggest concern was whether he could handle the face of Ligue 2. But he played against former Brighton captain Adam El-Abd. [when Newport faced Wycombe Wanderers] and there was a 50:50 in the corner. Ben went through him, came out with the ball and hit a 60 yard diag.
“I think he will play at the highest level and I think he will represent England. “
Former Leeds teammate Luke Ayling has also said he expects White to win an England appeal.
Ayling said: “I have no doubt that he will play for England soon and play a lot of games for them. He’ll probably go to one of the best teams in England and probably win the league and that’s because he’s so good, I think. “