Liverpool faces Tottenham in the Champions League final in Madrid looking to deliver the club's first trophy since 2012.
Klopp's men managed to secure 97 points in the Premier League this season, but fell short to champion Manchester City.
Alexander-Arnold feels a title could lead to a period of sustained success for Liverpool.
"This team is good enough to win leagues, to win Champions Leagues," the full-back said. "We've shown that across the last two seasons especially and we just need to get over the line now.
"I'm sure as soon as we get one, we'll be unstoppable and that's the focus for us – becoming a formidable team that is unbreakable."
Liverpool is in the Champions League final for the second straight season, having suffered a 3-1 loss to Real Madrid last year.
Alexander-Arnold, 20, said Liverpool had improved since that defeat to Madrid in Kiev.
"This time we know what it's all about, we understand everything around the game so we'll be more prepared in that respect," he said. "We're a more complete team. During the course of this season, we've shown a variety of ways to win and to conduct ourselves.
"When we score first, we're very hard to break down. If we need a late goal, we can produce it. If we need to manage a period of a game and take the sting out of it, we know what to do.
"If we're not at 100 per cent, Spurs can hurt us, but we will be leaving everything we've got on that pitch."