Cristian Romero has completed a medical ahead of joining Tottenham from Atalanta for £47m.
The Argentina centre-back, who will sign a five-year deal, will arrive in London to conclude the transfer on Friday morning.
The proposed transfer will make him the second most expensive signing in Tottenham's history after Tanguy Ndombele, who joined for £54m in July 2019.
Tottenham will look to sign one more defender ahead of the new season, with Colombia international Davinson Sanchez made available for transfer.
Spurs reached an agreement with Atalanta earlier this week after increasing their offer to £42.7m (€50m) plus bonuses, making a total package worth £47m (€55m) for Romero.
Romero made 42 appearances in all competitions last season as Atalanta finished third in Serie A and were runners-up in the Coppa Italia.
Atalanta have secured Juventus centre-back Merih Demiral as Romero's replacement.
Tottenham have already signed goalkeeper Pierluigi Gollini on an initial season-long loan deal from Atalanta, with the option to make it a permanent deal.
What can Spurs fans expect from Romero?
South American football expert Tim Vickery:
"Centre-back has been a real problem position for Argentina for years and just since the start of June when he first played, Cristian Romero has been greeted as the saviour. Even with just five caps, he's now the first defender on the team sheet for Argentina.
"He had a few injuries during the Copa America and only played three games, but Argentina didn't concede in those three games and had a splendid season at Atlanta, who are an attacking club. Their defence was often exposed but he came through that very well.
"He's combative - sometimes a little too combative - he's 23 so there's a lot of football ahead of him. Tottenham may be paying a little over the odds for him, but there's plenty to like about him. He's a real fighter."
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