Lukaku spoke after scoring twice in Belgium's 3-0 Euro 2020 qualifying win over Scotland on Tuesday.
Per The Independent's Luke Brown, while he would not comment specifically on Inter, he said: "I'll speak with my club and my agent Federico Pastorello to make the best decision. I am going to enjoy my holidays with my family now. I know what I'll do, but won't say it. We'll see. Do I expect a busy summer? Yes."
"I've had a difficult season at club level," he added. "I lost my place and haven't played much. But that is a phase in my career, and it will help me for the next step."
Lukaku started just 22 matches in the Premier League, though he did make 45 appearances in all competitions.
The 26-year-old might be a little disappointed with an overall tally of 15 goals, having netted 27 times in his first campaign at Old Trafford.
As James Robson of the Evening Standard noted, United are in a tricky situation with Lukaku, as they plan to continue with Marcus Rashford as their No. 1 centre-forward option next season:
Inter could be in the market for a striker this summer if Mauro Icardi leaves the San Siro.
Lukaku has his limitations, particularly when it comes to the technical side of the game, but he's typically a prolific goalscorer and can be effective when his strengths are played to.
He has been a force to be reckoned with for his national side:
In the Premier League, he has 113 goals in 252 appearances. That is not the record of a player who should be discarded lightly, even if he has struggled at times since joining United.
His record with Belgium—48 goals in 81 games—shows what he can do when the right service is provided for him.
Keeping him and recruiting players who can provide similar opportunities for him could be a wiser move than letting him go.