Marouane Fellaini admits Manchester United lacked "aggression" in the first-half of their defeat to Manchester City.

But the midfielder insists there's much for United to build upon after the setback.

"Everyone is disappointed today, which is normal after losing a derby, but this is the fourth game of the season and every team will lose games. We have to focus on the next game now and be ready," he declared to MUTV.

“The first half was difficult, but we created chances as well and it could have been 2-2 at the end of the half, so I think that is not the problem. The problem was we needed to be more aggressive to win the first and second balls but we didn't [do that]. However, the attitude was better in the second half.

“We didn't have the aggression in the first half, but that doesn't matter now. We have to focus on the next game and we have to win."