Authorities suspended or cancelled numerous international flights serving the US, Peru and Brazil at the Ezeiza airport south of the capital, hours after shutting off Jorge Newbery airport in Buenos Aires.
"We need the ash cloud to pass" before the airlines operating out of the airport, which serves domestic and regional flights, resume their operations, Transport Secretary Juan Pablo Schiavi told local television.
Argentina's LAN airline said in a statement that international as well as domestic flights were affected, including routes to Mendoza on the steps of the Andes mountains toward the Chilean border, and Ushuaia in the far south.
In Uruguay, 15 international flights were cancelled at Montevideo's international Carrasco airport, largely affecting flights to Chile and neighbouring Argentina and Brazil.
Brazilian carriers Gol and Tam both cancelled their flights to Buenos Aires and Montevideo, company officials said.
Air traffic in the southern hemisphere has been hit hard in recent months. Airports in Buenos Aires and Montevideo and later those in Australia and New Zealand were paralysed when the volcano high in the Andes roared back to life in June after sleeping dormant for half a century.
Since June, most airports in Argentina have been forced into shutdowns at some point due to dangerous ash threatening the safety of commercial airliners.
The ash cloud also dampened hopes of a good tourist season at the Argentine ski resort of Bariloche, some 1 600km southwest of Buenos Aires and just 100km southeast of Puyehue, as flights were cancelled and pristine snow was darkened by the spewing volcano.
Ash poses a significant threat to aircraft because once sucked into engines, it can be transformed into molten glass by the high temperatures and potentially cause an engine to fail.
The eruption of the Icelandic volcano Eyjafjoll in 2010 caused the greatest shutdown of air space in peacetime Europe, with more than 100 000 flights cancelled and eight million passengers affected.