Speaking at a news briefing, Adam Niedzielski said the fourth wave was likely to peak "this week or next," the state PAP news agency reported.
Niedzielski said that Wednesday's figures, showing over 28,000 infections and more than 18,000 hospitalisations, were "concerning" and on track to "challenge the capacity of the healthcare system."
"In our view, the current situation is dangerous," he added.
Niedzielski told reporters that the fourth wave was expected to crest "at around 25,000 cases this week or at 30,000 to 35,000 cases next week," and then subside.
However, "we must also be prepared for a scenario where infections don't fall," he cautioned.
"If cases don't begin to fall, then restrictions will definitely be stepped up," Niedzielski stated.
"Under such a scenario, decisions may have to be taken in early December," he added.
Poland on Wednesday reported 28,380 new coronavirus infections and 460 more deaths related to COVID-19, bringing the country's total number of cases during the pandemic to 3,406,129 and fatalities to 81,688.