The club has reached an agreement with the US Soccer Federation to release Pochettino and his coaching staff once their current international commitments conclude.

He will oversee two Concacaf Nations League fixtures against Haiti before travelling to Manchester on Wednesday.

Pochettino replaces Michael Carrick, who was dismissed yesterday, and becomes the eighth permanent manager to take the Old Trafford hot seat since Sir Alex Ferguson's retirement in 2013.

He is expected to lead his first training session on Thursday ahead of his opening match in charge.

The deal to prise Pochettino from his international post is understood to have cost United roughly £7million in release clause payments to the US Soccer Federation.

This comes on top of approximately £5million already spent on terminating Carrick and his backroom team's contracts.

The total outlay of around £12million is particularly galling given that both managers were out of contract during the summer, meaning the same managerial swap could have been executed at no cost just months earlier.

Pochettino had only extended his agreement with the US national side three months ago, committing through to the 2030 World Cup.

His new contract at Old Trafford runs until the summer of 2029, with the club's hierarchy, including chief executive Omar Berrada, sporting director Jason Wilcox and owner Sir Jim Ratcliffe, finalising the appointment following a meeting in Monaco on Wednesday.

The Argentine inherits a squad in dire straits, sitting 18th in the Premier League table with a solitary victory from their opening 10 fixtures and just eight points accumulated.

It marks the first time since 1986 that United have found themselves in the relegation places at this stage of a season.

Carrick's tenure followed a dramatic arc.

He initially stepped in on an interim basis in January after Ruben Amorim's acrimonious departure, winning 12 of 17 matches and steering United to a third-place finish that secured Champions League qualification.

That run earned him a permanent two-year contract in May.

Yet results collapsed this term spectacularly.

Losses to Bournemouth and Chelsea compounded the malaise, and a chaotic 4-4 draw with Aston Villa proved to be Carrick's final match at the helm.

Pochettino brings a wealth of English top-flight experience from his time at Southampton, Tottenham and Chelsea.

His five-year spell at Spurs proved the most celebrated, culminating in a run to the 2019 Champions League final, while he also claimed the Ligue 1 title and Coupe de France at Paris Saint-Germain.

He takes charge of a squad bolstered by considerable recent investment, with Matheus Cunha, Bryan Mbeumo, Benjamin Sesko, Carlos Baleba and Youri Tielemans among the signings made in recent transfer windows.

His tenure begins with a trip to Anfield to face Liverpool on November 22, followed just three days later by a Champions League encounter against Sporting, before fixtures against Brentford and Newcastle.