The restrictions to be lifted in the so-called 'phase two' of reopening might include the closure of shopping centres, cafés, and restaurants, or the closure of schools to elder pupils.
But Frederiksen said the government wanted to be cautious, and take decisions based only on the situation at the time the lifting is scheduled to take place.
“We are only going to take a decision very close to May 10,” she told the 21 Søndag programme on Denmark's public broadcaster DR.
“It is insidious, this disease, and things might look different in a few days. It takes time to go from getting infected to becoming seriously ill.”
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In the interview, Frederiksen explained that if the government moved either too soon or too late in lifting restrictions, it risked causing damage, either to people's health or to the economy, making the timing crucial.
“If you go too fast and become impatient and open up too much, then we risk the infection spreading and us losing the control we have achieved the first time around. But conversely, if we are overly cautious and slow, then there is also a risk involved.”
Denmark's parliamentary parties are currently discussing the next stage in the country's opening, based on information provided by the country's infectious diseases agency SSI.
Frederiksen said health would be the first consideration, followed by what would have the most economic impact, followed by how the measures impact social life in Denmark.
The opposition Liberal Party has called for shopping centres, restaurants and cafés to be next to reopen.