The Health Ministry confirmed 6,840 new coronavirus cases on Tuesday, lifting Argentina above 300,000 infections.
Since the pandemic arrived in Argentina, 305,953 people have now been infected with Covid-19, according to government data. The true number is likely to be higher.
Officials also said Tuesday that 235 people had died since the previous day's health briefing, one of the highest daily tolls to date.
In total, 6,048 deaths have been recorded.
Numbers have surged over the past two months in Argentina, with greater strain being placed on the health system. Tuesday's update comes on the back of a mass anti-government rally the previous day in several cities across the country.
Officials in the Alberto Fernández administration were critical of those who attended the rally, saying the protest could aggravate the number of infections.
Nevertheless, pressure is building on the government to relax quarantine restrictions, given the economic turmoil facing the country, which has been in recession since 2018. The economy is expected to contract by more than 10 percent this year.
A poll from Giacobbe & Asociados published Tuesday, based on consultations with 2,500 people last week, reported that 44 percent of those quizzed disapproved of the government's most recent extension of the lockdown, with only 43 percent approving of the extension.
The Health Ministry says that more than 223,000 people have recovered from the virus after infection. The fatality rate in Argentina is 115 people per one million inhabitants, the third lowest in the region after Uruguay and Paraguay.