Chido Obi-Martin has confirmed he has signed for Manchester United from Arsenal with a post on Instagram.

The 16-year-old forward caught the eye with his prolific form in Arsenal's youth teams last season before turning down the opportunity to sign professionally with the club.

He scored 10 goals in the 14-3 win over Liverpool's U16s last November; then, between the start of March and the end of May, he netted 28 goals in 10 games in the U18 Premier League.

"Very happy to sign with this amazing club, time to focus and achieve all my dreams," the post on social media read.

"Thanks to everyone who has helped me get this far."

ESPN reported earlier this week that the transfer took a long time to agree due to compensation having to be agreed between the clubs and the Premier League needing to ratify the move.

Obi-Martin is set to begin with United's Under-18 side.