"Calais visit confirmed: [Frans] Timmermans and [Dimitris] Avramopoulos to go on 31 August," Milica Petrovic announced via a Twitter microblog post, which Avramopoulos confirmed in his own post.
Petrovic added that Avramopoulos was planning a trip to the eastern Greek island of Kos "in coming days."
The Aegean Sea island is another European frontier reeling from an influx of refugees fleeing crises in the Middle East, North and Sub-Saharan Africa.
An estimated 4,000 undocumented immigrants are living in camps near Calais in their attempt to reach the United Kingdom.
Several deaths have been reported since June during nightly attempts to board trains and trucks crossing the Channel Tunnel from Coquelles, France, to Folkestone, Kent, in the UK.
The European Commission is considering a $2.6-million assistance request from France, a portion of which Paris said would be used to accommodate some 500 asylum seekers.