Defeats to Tottenham and Stoke have left Liverpool in fifth place with 13 points, six points off leaders Manchester United and second-placed Manchester City.
"We have no limit and want to stay in the top four. But winning the Premier League is now very difficult," The Uruguayan star said.
"The main reason why it is so difficult is because the two Manchesters and Chelsea are unreachable. But we can win the Cups."
Suarez moved to Liverpool from Ajax, where he scored 111 goals in 159 appearances.