The Brazil international is linked with a move to United, with champions Manchester City having almost landed the 25-year-old in January.

Speaking at a news conference on Friday (AEST), Fred said he was yet to decide his next move – and will now wait until after Russia 2018 to make an announcement.

"There's been some advanced talks since January, when I almost went to Man City," he said.

"United talked to my staff and Shakhtar. But besides these strong news, my head is entirely with the World Cup.

"Gilberto Silva [his agent] is a guy in which I trust, he deals with all off-pitch stuff. My family is always well informed, too.

"I don't know what I'm going to choose, maybe I'll decide better after the World Cup."

Fred  - who has won seven caps for Brazil but has not started for his country since the 2015 Copa America - joined Shakhtar in 2013 from Internacional.