The three countries refuse to recognize the new Paraguayan government after Lugo was impeached Friday, The Wall Street Journal reported.
Argentine President Cristina Kirchner called the impeachment process a coup and recalled her country's ambassador to Paraguay "until democratic order is re-established," the Argentine Foreign Ministry said in a statement Saturday.
Brazil's Foreign Ministry said in a statement the impeachment process compromised "the fundamental pillar of democracy."
Venezuelan President Hugo Chavez halted oil shipments to Paraguay and moved to cut diplomatic ties.
Lugo was removed from office after a two-day trial on grounds of "poor performance." Paraguay's Congress said Lugo failed to adequately handle clashes between squatters and police that resulted in deaths of each.
The ousted president called his impeachment a "parliamentary coup."
"The dictatorship isn't only military, but also parliamentary," he said. "They have deposed democracy ... . they haven't respected the popular will, and that is anti-democratic."