Mercedes has been "working day and night" to avoid a repeat of the mechanical problems that beset Lewis Hamilton in the last two races, Paddy Lowe has said.

Nico Rosberg has won all four races so far this season for Mercedes, but with Hamilton's car suffering technical issues during the Chinese and Russian Grand Prix weekends, Lowe emphasised that the target in Spain is for a "clean weekend".

"The highest priority is to come back with our MGU-H problem solved, having had a repeat fault over the past two race weekends," said Lowe, Mercedes' technical executive director. "The team has been working day and night to understand it and we're targeting a clean weekend all round."

Meanwhile, Lowe added that the race in Barcelona presents a number of challenges, even though the teams all know it very well from winter testing.

"Barcelona itself is a circuit which is very demanding of all aspects of car performance. There's a common saying in Formula One that if you're quick around Barcelona, you'll be quick everywhere. This makes it an important landmark in the season to see where you stand in performance terms, as most teams will be bringing a range of upgrades," he continued.

"Of course, we've all been to this circuit already in 2016 during winter testing - but it's a very different track in May compared to how it was back in March. It will be much warmer and the tyres will behave differently.

"We have the hard, medium and soft compounds to choose from, which presents some challenges. The soft will be essential for qualifying but not be a great race tyre, so determining the optimum strategy will be a focal point.

"Qualifying and race starts will also be important, as it is notoriously difficult to overtake at this circuit."