The next few days will be "critical" in deciding what steps will be taken to stop the spread of Covid-19 in Scotland, Nicola Sturgeon has said.
The first minister said the virus was on the rise and was now spreading "quite rapidly".
She said it was likely that some "hard but necessary" decisions would need to be taken in the coming days.
"If we want to avoid another full-scale lockdown, doing nothing almost certainly isn't an option," she said.
Ms Sturgeon warned that the country was following the path of France, which four weeks ago was in the same position that Scotland is now.
It is now seeing 10,000 new cases a day, with hundreds of people in intensive care and the number of deaths increasing.
Weekend 'will be critical'
"We must make sure we interrupt that and don't end up where they are now," she said. "We are facing the risk again of expediential growth in Covid."
"No-one wants to see another full-scale lockdown."
She asked people to abide by the current rules.
"It may well be that if we are to interrupt and break this growth we will have to do more in the next few weeks," she added.
"This weekend will be critical in the assessment of how best to do that."
Ms Sturgeon said there had been 203 positive tests in the past 24 hours, and that one person who tested positive had died. That took the total number of deaths in Scotland under the measurement being used to 2,502.
"The bottom line here is this virus is on the rise again," the first minister said.
"Cases are rising quite rapidly. The percentage of tests is not as high as March but is rising. And the R number is now above 1."
She said she had met a group of senior Scottish government officials to assess the situation and that discussions would take place with the four UK nations in the coming days.
The first minister said she had also asked the prime minister to stage a Cobra meeting this weekend.
Ms Sturgeon said the WHO warned on Thursday that weekly Europe-wide cases were higher than they had been in March.
"The virus could get out of our grip again but it hasn't happened yet and we have time to prevent it from happening," she said. "That is down to the government and all of us."
Second wave
The leader of the Scottish Conservatives said he would support the introduction of any measures needed to help defeat the virus.
Douglas Ross told BBC Scotland that every available option should be considered.
"We have seen the issues that we have if we don't get on top of it, and if we don't make the difficult decisions to reimpose some restrictions," he said.
"So everything that has to be done must be done to ensure we don't get a second wave of this pandemic that puts pressure on our hospitals and our NHS again.
"I support everything that can be done to support beating this terrible pandemic."
The first minister urged people to take part in a UK-wide Covid infection survey.
Up to 15,000 people in Scotland will be tested every fortnight and households will be randomly selected for the survey and invited to participate.
Those taking part will do their own tests and some will be asked to provide blood samples.
The tests will continue for up to a year and will help scientists see how many people are infected with the virus over time and how many people will ultimately have the infection.