Belgium boss Roberto Martinez has urged Romelu Lukaku to leave Manchester United this summer, and said the forward was "targeted" due to the club's underwhelming performances last season.

Lukaku is a transfer target for new Inter Milan chief Antonio Conte -- with the ex-Everton man having recently labelled the Italian the "best manager in the world."

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And Lukaku's international boss has said it would be better for both the player and United to part ways this summer.

"I think it is clear he [Lukaku] is ready for a new challenge," Martinez told HLN. "In his case, a transfer would be good for both the player and the club.

"And if two parties benefit from it, a move away usually happens. Serie A seems to be a good choice for him, although I think he can handle any league.

"I certainly don't think his transfer to Manchester United is a failure. The team did not perform to its capabilities and important players -- such as Romelu, but also Paul Pogba -- were targeted."

Speaking after Belgium's 3-0 Euro 2020 qualifying victory over Scotland, Lukaku said he had "always dreamed" of playing in Italy.

"I was always a big fan of the Italian league," the 26-year-old had told Sport Mediaset. "I have two leagues which I always dreamed about which are the English league and the Serie A.

"So for me the Serie A is my favourite league as well -- I love Italy."