Friday's draw paired the two remaining Premier League sides together, with Anfield hosting the first leg on April 4 before the teams head to the Etihad Stadium six days later.
Liverpool are the only team City have lost to in the Premier League this season, with Pep Guardiola's men closing in on the title to add to their EFL Cup crown won against Arsenal.
Jurgen Klopp also has a better record against Guardiola than any other manager, but Van Dijk still expects the Reds to face a difficult task against City.
"Everybody knows that anyone we get is going to be very hard," Van Dijk, who became the world's most expensive defender when he joined from Southampton in January, told Liverpool's website.
"Man City are a very good team, very hard to play against and we need to be 100 per cent or even better to beat them over two games. We can prepare for that when the time comes."
Manchester City have never been further than the semi-finals of the Champions League, but Gundogan hopes his experience of the tournament can help his team progress against Liverpool.
"At the end you need to play against the best to win this trophy," Germany international Gundogan said to City's website. "You must compete against the best to get to the final and, of course, to win it.
"I was lucky enough to play in the Champions League final in 2013 with Borussia Dortmund, unfortunately we lost [to Bayern Munich], so obviously I can't wait to try and get to a final and win it this time - that is my main target.
"Fortunately, we won the EFL Cup and we are very happy about it, to gain our first trophy quite early in the season. This is now in our hands, nobody can take it away.
"For us, this is just the beginning. We are in good shape to face the elite clubs in Europe, but I wouldn't say we are there just yet.