Argentina's customs agency suspended operations at the transshipment zone at the Km 171 mark in the Parana Guazu river.
The agency said the area lacks port authorization required by Argentinian law, according to a document seen by Argus.
The suspension will take effect 30 days from 26 June, after which all customs-related activities must be redirected to officially authorized ports.
Km 171 is a critical location for Argentina and Paraguay, serving as a hub for ship-to-barge cargo transfers, particularly of oil products. It is especially important for Paraguay, which relies heavily on river transport for its imports and exports. Argus assesses diesel and naphtha fob at Km 171.
The suspension could disrupt regional trade flows and increase pressure on alternative ports. Area shipping agents and shipowners are already questioning the measure and market participants said meetings to discuss the matter are expected in the coming weeks.