Ferrari has slipped back in the last two events, with the two cars finishing ninth and 10th at Silverstone, and seventh and eighth in Hungary last weekend.
However, Vasseur says the Italian outfit should just focus on its own performance and not get too hung up about the pacesetters.
"Red Bull are in front but I think the feeling was quite the same when Mercedes was in front a few years ago,” he said.
"The most important thing is to be focused on ourselves, to try to get the best from what we have, to minimise the mistakes, do a better job and then comes what will come.
"To catch up, it's not that you are thinking about the Red Bull and thinking what do we have to do? We have to work on ourselves.
"We are developing, we are developing on every single direction, we are trying to improve aero, suspension and whatever we can do, and we are pushing like hell to do a better job.
“But if you have a look also, and I think this is crucial, with the bouncing and so on it's not when you are bringing an upgrade that you are making a huge step forward.
“We brought big things in Barcelona, and we were potentially better the week after. I think Alfa Romeo brought something last week or two weeks ago, and they did a very good job this weekend [in Hungary], at least in quali.
“It means that the understanding of the upgrade is also crucial. And it's not just about making a headine package."
Source: Autosport