​Manchester United have officially confirmed the deal to sign Arsenal forward Alexis Sanchez, while Arsenal have also announced the signing of Henrikh Mkhitaryan from the Red Devils on a long-term contract.

United attacker Mkhitaryan has agreed to move to the Emirates as part of the transfer that takes Sanchez to Old Trafford, with the deal being completed in a rare straight swap agreement. 

Sanchez becomes the first player since Robin van Persie to make the move from the Emirates to United, and will be handed United's famous number 7 shirt. Reports have been rife over the details of his contract, with some suggesting he has signed a deal ​worth £14m-a-season, but sources from the club appear to suggest he will pocket around £300,000-a-week

Meanwhile Mkhitaryan, who joined United from ​Borussia Dortmund a season and a half ago, will join up with another former United forward in Danny Welbeck at the Emirates.

The Armenian turned 29 recently, and was a part of the United squad that won both the EFL Cup and Europa League last season. Arsene Wenger is believed to have held a long-standing interest in the player - he even tried to sign him before United snapped him up initially - and Arsenal were intrigued at the prospect of taking him in exchange for Sanchez.

It's believed no fee has been exchanged between the clubs, with Mkhitaryan's value enough to satisfy the Gunners. 

Manchester City had been publicly courting Sanchez for several months, with Pep Guardiola's side widely expected to sign him when his ​Arsenal contract was set to expire in June 2018. City had agreed personal terms with Sanchez and a large signing on fee as part of their deal, but United then swooped in to try and sign him six months early.

Jose Mourinho's side however sensed an opportunity to beat their city rivals to Sanchez earlier this month, offering a far more handsome financial package than the ​Premier League leaders were willing to. City then walked away from the deal. The Red Devils also fought off late reported interest from league rivals Chelsea.

Sanchez ​called Manchester Untied 'the biggest club in the world' upon his arrival and insisted he is looking forward to working with new boss Jose Mourinho, while ​Mkhitaryan claimed he's always dreamed of playing for Arsenal.