Arsenal manager Mikel Arteta believes the Gunners have to strengthen in the transfer market if they are to topple Manchester City as Premier League champions next season.
Arteta's men topped the table for much of last season, but faltered down the stretch after suffering injuries to key players.
City went on to seal their fourth Premier League title in five years and complete the treble by winning the FA Cup and Champions League.
Both clubs are reportedly in a bidding war for West Ham captain Declan Rice, while Arsenal are also set to land Kai Havertz from Chelsea.
"That is our ambition," Arteta told Marca on his hopes of winning the title.
"We know the difficulty: it's the best league in the world and next season is going to be the toughest league in Premier League history.
"Why? It already was last year. I've been here for 22 years and I've never seen a competitive level like that. So much quality, so much organisation, so many resources, so many good coaches
"That's the level and to win the Premier League you have to be the best. That's why you have to strengthen."
Few expected Arsenal to even pose a title challenge having finished outwith the top four for the previous six seasons.
But Arteta admitted he is still hurting after leading the Premier League most of the way from August through the April.
"To this day, it still hurts me deep inside not to have won the Premier League after 10 months of fighting with City," he added.
"There were three or four injuries to important players and from then on, everything got complicated. When we had the full team, we were consistent. As soon as problems came, it wasn't enough for us.
"Our opponent was the best team in the world, the best squad in the world, the best coach in the world.
"We had no choice but to accept it and shake hands with the champion."
