Romelu Lukaku is confident Manchester United's squad already has enough to challenge Manchester City for next season's Premier League title, suggesting investment is not necessary.

Although United have produced a marked improvement in the Premier League from last season's sixth-place finish and look set to end the campaign second, they are some way adrift of City.

Pep Guardiola's men were crowned champions last week as a result of United's shock defeat to rock-bottom West Brom at home.

A win for City over Swansea City on Sunday will restore a huge 16-point gap at the top of the table, but Lukaku insists they are not that much better than United.

Jose Mourinho's side beat Tottenham 2-1 in Saturday's FA Cup semi-final and Lukaku feels the only thing standing between United and challenging City is producing such performances on a consistent basis.

When asked how much investment United need to challenge City, Lukaku told reporters: "I don't know, you'd have to ask the manager.

"I'm really confident in my team-mates. I think we can do it with the team we have now, but we should have shown more consistency throughout the season

"For us now it's up to us to be more consistent and the manager needs to see if he has to add more players, but with the players we have now, I think we have enough – we just have to be more consistent.

"It was a strange season for us. If we had more consistency we could have been up there with Manchester City now.

"But we know what we have to improve for next season and winning games like this is what we do.

"If you look at games we have played against the top six, we have won a lot of them so when we played against Tottenham we were confident as well. We have to keep going like that."

Although Premier League success has long looked unattainable this season, United are at least closing in on ending the campaign with a trophy after victory at Wembley.

Winning the FA Cup would be no replacement for a league title triumph for Lukaku, however.

"Well, I want to win the title, that is the thing," Lukaku added.

"Winning the FA Cup would be nice, but I don't want to talk about [it]. I just want to end the season well, hopefully take second and that will prepare us really well for the final."