"I can assure you as commander in chief of the armed forces that, institutionally, there is no danger of a military coup," he said.
"There could be small military groups that are connected to or could be used by the political class, but institutionally, the military does not show any intent of reversing the process of democratic consolidation."
While Lugo's election win was a shock to the Colorado Party, the president's supporters are still in the minority in congress and politicians opposed to Lugo have sought to remove him from office before his term expires in 2013.
A majority of politicians in congress said last week they were set to call for an impeachment trial over comments that Lugo allegedly made which some interpreted as a call for class warfare.
Lugo, a former Roman Catholic bishop, has denied making such a statement, but he said on Tuesday that Paraguay's politicians should do more to help those in the country who are living in poverty.
He said that the rich "[sit] comfortably in air-conditioned offices" while the poor "survive on just one meal a day if they are lucky ... without safe drinking water, surrounded by misery".
Lugo does not have enough votes in congress to make sweeping changes in Paraguay and even some of his supporters have said that he needs to do more to overcome his opponents.
Al Jazeera's Latin America Editor, Lucia Newman, said Lugo's position had become increasingly precarious in recent weeks, with support amongst his own constituency dropping steadily over his inability to carry out land and other social reforms, and after his admission that he had fathered at least one child while still in the priesthood.