The Red Bulls announced on Wednesday that MLS and the 2007-08 Spanish La Liga runners-up have agreed in principle to a transfer fee with the 18-year-old striker.

Altidore must agree to personal contract terms and undergo a medical before the deal can be completed.

He has three goals in eight appearances for the Red Bulls this season. In his career, he has 15 goals in 37 appearances.

He also has one goal in two full international appearances for the United States.

The value of the transfer has not been disclosed but it has been reported that the fee could dwarf the record paid for an American player, when Barclay's Premier League side Fulham signed Eddie Johnson for £3million.