Toto Wolff has warned Mercedes's rivals that the championship leaders are out to increase their advantage at next weekend's Spanish Grand Prix.
Mercedes has claimed every pole position and victory in 2014, with Lewis Hamilton and Nico Rosberg completing three successive 1-2 results, as well as having led every racing lap.
But Wolff insists that Mercedes is aiming to improve their current situation.
"We are now four races into the 2014 season and hold a strong position in both Championships," said Wolff.
"However, the first European round of the year always provides a prime opportunity for teams to arrive with improvements to their cars. Of course, we are no different to any other team in that respect and our aim must be to increase the advantage we enjoyed at the last race in China."
Wolff believes that Mercedes has to react to the improvements made by their rivals.
"We have seen already that our rivals are relentless in their efforts to close the gap," he said. "As a team, it is up to us to rise to that challenge: to take that relentless mentality to an even greater extent than those around us.
"If we are to build a sustained level of success in this sport, any small advantage must be seen as a platform upon which to build a bigger advantage. We head to Barcelona on good form and in high spirits. But, most importantly, we approach the next race weekend as we approached the first: in the knowledge that there is still a long season ahead and anything can happen."