Mercedes boss Toto Wolff says the team has "zero room for error" despite its strong start to the season due to the close proximity of Ferrari.

Despite Mercedes winning the opening two races of 2016 Ferrari has shown a clear improvement on the performance side, though a retirement in either race has highlighted reliability concerns. The world champions already enjoy a lead of 50 points in the constructors' championship but Wolff thinks Ferrari has plenty left in the tank for later in the year.

"With Ferrari increasingly breathing down our necks, as we saw in Bahrain, there is zero room for error," Wolff said. "Remaining energised is now more important than ever -- and we all have plenty to keep us on our toes in that respect. With just two races down and nineteen to go, I wouldn't say there is momentum on one side or the other.

"But what is clear -- and very exciting for the team and the sport -- is that we have two drivers high in confidence who will provide us with plenty of entertainment over the coming months."

While Nico Rosberg has claimed two victories, Lewis Hamilton has compromised both this year's races with bad starts from pole position. Wolff does not think Mercedes can afford to get carried away with its strong results so far as there are areas it can improve.

"After two races, we find ourselves in a strong position. Our car has proven itself to be competitive in a range of conditions once again -- but also reliable even at this early stage, which is a tremendous achievement. But there is a long way to go and we have by no means been flawless in every area so far."