Striker Romelu Lukaku believes his recent goal drought at Manchester United is a result of the club not playing at the level they did at the start of the Premier League season.

Lukaku has scored seven goals from 11 league games but has failed to find the net in the last four as United, who have lost two of their last three matches, dropped to second in the table, eight points below runaway leaders Manchester City.

The 24-year-old struck a brace for Belgium in Friday's 3-3 draw in the friendly against Mexico and said he hoped to regain his scoring touch to help his club catch up with the leaders.

"We started by blowing teams away, being dominant and creating chances. But in the last few weeks, we didn't play at the same level and that made it more difficult for me," Lukaku told Sky Sports.

"That's the sort of thing you have to go through in the season, but now there are players coming back from injury and hopefully we can deliver performances even better than at the start of the season. We can create more chances and goals."

Lukaku said the return of striker Zlatan Ibrahimovic from injury will motivate him to do even better. The Swede is currently working his way towards regaining full fitness after suffering a knee injury last season.

"It motivates me really because he's another good player to add to the squad... When you face a team like us, it's difficult for opponents," Lukaku said. "Ibrahimovic coming back will help us to chase Manchester City (in the title race)."

Lukaku's brace in Brussels took his international tally to 30 goals to match Bernard Voorhoof and Paul van Himst and he could overtake them when Belgium face Japan in a friendly on Tuesday.

"I feel great... I was born to score," added Lukaku. "I don't think many strikers of my generation have as many goals as me. I am like a leopard in the box."