Liverpool head coach Arne Slot has said the club are already working on strengthening in the summer transfer window but insists he is happy with his squad.

Slot signed just two players after arriving at Anfield from Feyenoord Rotterdam last summer; forward Federico Chiesa and goalkeeper Giorgi Mamardashvili, who is spending this season on loan with La Liga side Valencia.

Despite the club's lack of transfer activity, Liverpool have excelled under Slot this season and are top of both the Premier League and Champions League tables.

Liverpool have yet to bring in any reinforcements in the January transfer window, however Slot has revealed it is likely to be a different story in the summer.

"Liverpool should always be competing for a league title, we should always be competing for the Champions League," he said in an interview for the BBC'S Football Focus. "I'm hoping I will be able to keep the club at that level.

"I know people sometimes question this because they haven't seen us doing a lot in the transfer market in the summer and now in the winter as well. There's a reason for that -- because we're happy with the squad.

"But I do know we're definitely working on strengthening in the summer."

Slot also heaped praise on captain Virgil van Dijk, who is out of contract at Liverpool in the summer, and admitted his team have defied even his own expectations with their success this season.

"Everybody here in England would tell you that Virgil van Dijk is the best defender in the world," he said. "In Holland, he got a bit more criticism than he gets over here in England. I was, in a very positive way, surprised how good he was on the ball and how he could play football through the lines.

"From the first day I was like 'wow, this is definitely another level than I'm used to.' But people in England were used to this."

Slot added: "You don't think after 20 games we will have that many points and I wasn't expecting us to be top with the margin we have.

"It's always nice to be up there, but nobody would have expected this. I'm the last person who would have expected [Manchester] City to have such a bad run."