Pastor Maldonado admits that the Montreal circuit is one of the toughest on the F1 calendar ahead of this weekend's Canadian Grand Prix.

Maldonado heads into the event still seeking a first points finish of the season, with Williams having again failed to trouble the scorers last time out in Monaco.

Speaking ahead of the Canadian race, Maldonado said he was looking forward to getting back on track following his heavy shunt in Monte Carlo for a weekend he expects to be one of the more challenging of the year as drivers come to terms with a constantly changing track surface.

"Montreal is definitely one of the most challenging tracks, especially when it rains as the downpours can be quite heavy," he said. "Obviously this causes changes to the strategy regarding pit stops and tyres. It also makes life much more challenging on the track because there are certain places where puddles form. In the past there has been a high frequency of safety cars during the race as well which will again affect race strategy.

"The track itself starts off very dirty on Friday because it's only used once a year and it isn't really until the Saturday qualifying session that more grip can be found after we have had a chance to lay down more rubber. It's interesting to drive on a track that changes so much as the weekend unfolds and the layout feels a bit like a street circuit which gets the adrenaline pumping."

Team-mate Valtteri Bottas meanwhile will be competing at the Circuit Gilles Villeneuve for the first time and he admitted that getting up to speed quickly would be key to his chances of a strong weekend.

"This will be my first time driving at Montreal and I'm looking forward to the challenge," he said. "It's similar to the last race in Monaco in some respects, being a street circuit with a number of the corners and straights very close to the walls. The challenge is therefore to quickly find the cars limit and use as much of the circuit as you can, without taking too many risks. I'm particularly looking forward to the last corner, the wall of champions, which is very iconic.

"As this is my first time driving the track, Friday morning is going to be important to get the right car setup. There are long straights on this circuit so good traction is needed out of the slow speed chicanes, and you also need really good straight line speed, especially in the race. If you have better straight line speed than your competitors, the racing will be much easier for you to defend and overtake so we need to find a good compromise between downforce and drag."