Speaking to TheParliament.com on Tuesday, Jean-Luc Vanraes went so far as to concede that the city's prosperity "is a consequence of the European presence".
His comments, just two days before the start of the Belgian EU presidency, will be seen by some as countering criticism of the cost to Belgium of the EU and its various institutions and bodies.
Vanraes, responsible for external relations, said, "The EU brings a huge added economic value to the city. Many large companies establish themselves here and the result is that this region has become the country's main economic powerhouse.
"We have to keep it this way. The present prosperity of our region is a consequence of the European presence. But that does not mean we have to stand still.
"For a city like Brussels, the failure to evolve in line with others irrevocably signifies lost ground. The expansion of the EU will increase competition with Brussels so we have to make even more use of our European assets, tap new markets and attract new companies and continue to build up our image.
"The aim is to ensure Brussels can remain the gateway to Europe."
He was speaking at the press launch of the various events and initiatives planned to mark the contribution Brussels will make to the six-month rotating presidency.
Belgium takes over from Spain at the helm of the presidency from 1 July. The presidency has lost some of its powers under the Lisbon treaty but, even so, remains an important part of the EU decision-making process.
He said that the Brussels "brand" is worth some $540bn to the city, adding that 200 European regions have offices in Brussels while it also plays host to 160 ambassadors, 2500 diplomats and 15,000 lobbyists.
"If one adds up all the employees and their families who have some connection with the international community, you arrive at a figure of 105,000, or 10 percent of the population of the city," he said.