Monaco have completed the £35m signing of striker Folarin Balogun from Arsenal on a five-year deal.
The 22-year-old United States forward returns to France after scoring 22 goals on loan at Reims last season.
Balogun had not featured for Arsenal in the Premier League at the start of this season despite first-choice striker Gabriel Jesus being injured.
He signed professional terms with Arsenal at 17 and made two top-flight appearances with the club.
In Jesus' absence, Eddie Nketiah started the first two matches of the campaign, while Leandro Trossard was favoured in Saturday's 2-2 draw with Fulham.
In a statement on their website, Arsenal said: "We thank Folarin for his contribution to Arsenal, through our academy into the first team, and wish him the best of health and happiness in his new chapter at Monaco."
Born in New York, Balogun moved to London as a child and came through Arsenal's academy system.
He played for England age group sides through to under-21s, earning 13 caps at that level, before electing to play for the United States at senior level.
Balogun had loan spells at Middlesbrough and Reims and was linked with Chelsea before Arsenal accepted Monaco's offer.
