The suspect was in police custody, Van Der Sypt said.
A police official told AFP that the attacker tried to escape the scene but was shot by a police officer. A third officer was injured when he tried to stop the man, the official said.
The attack happened in the Schaerbeek area in the north of Brussels.
It comes two months after two policewomen were wounded in the southern Belgian city of Charleroi by a machete-wielding man who shouted "Allahu Akbar" (God is greatest).
That attack was claimed by the Islamic State (IS) group.
Brussels is still reeling from IS suicide bombings at the city's airport and a metro station in March which killed 32 people.
A bomb-making factory for the Brussels bombings and the November 2015 attacks in Paris was located in Schaerbeek.
Business Standard has always strived hard to provide up-to-date information and commentary on developments that are of interest to you and have wider political and economic implications for the country and the world. Your encouragement and constant feedback on how to improve our offering have only made our resolve and commitment to these ideals stronger. Even during these difficult times arising out of Covid-19, we continue to remain committed to keeping you informed and updated with credible news, authoritative views and incisive commentary on topical issues of relevance.
We, however, have a request.
As we battle the economic impact of the pandemic, we need your support even more, so that we can continue to offer you more quality content. Our subscription model has seen an encouraging response from many of you, who have subscribed to our online content. More subscription to our online content can only help us achieve the goals of offering you even better and more relevant content. We believe in free, fair and credible journalism. Your support through more subscriptions can help us practise the journalism to which we are committed.
Support quality journalism and subscribe to Business Standard.