The suspect identified only as M.G. appeared Monday morning before an investigating judge who ordered him held in the case, it added.
The suspect denies any involvement in the alleged plot.
A source close to the investigation told AFP the suspect is a Belgian man of around 40 years old who had "raised suspicion because of his behaviour".
He had been seen "scouting" the embassy area before he was arrested, the source added.
Jihadists have staged a number of attacks in Brussels, which hosts the headquarters of the European Union and NATO.
The worst was on March 22, 2016, when suicide bombers killed 32 people and wounded hundreds of others at Brussels airport and a metro station near EU buildings.
The Islamic State group claimed responsibility for the twin attacks.
Several other attacks, some of them claimed by IS, have also targeted Belgian police or soldiers.
The US embassy was not immediately available for comment.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)
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