Ministers are looking into imposing time limits for children using social media, according to Culture Secretary Matt Hancock.
He said the negative impact of posting and consuming content online was a "genuine concern".
Mr Hancock said more needed to be done to safeguard young people and suggested an age-verification system.
He said there would be a new legal requirement for companies to ensure users were over 13 years old. The details of how such a scheme would work are still being worked out.
"There is a genuine concern about the amount of screen time young people are clocking up and the negative impact it could have on their lives," he told the Times.
"For an adult I wouldn't want to restrict the amount of time you are on a platform but for different ages it might be right to have different time cut-offs."
Mr Hancock suggested varying cut-off times for different ages on services such as Facebook, Instagram and Snapchat.
The platforms already specify a minimum age of 13 but children only have to falsify a date of birth to gain access, despite critics claiming most sites are able to identify underage users from their browsing habits.
Mr Hancock said it was "not beyond the wit of man" to develop an age-verification system for children.
A 2017 survey by Ofcom found that 83% of 12-18-year-olds and 39% of 8-11-year-olds had their own smartphone, and that 23% of 8-11-year-olds had a social media profile compared with 74% in the older age group.
It also found that social media use sometimes brought problems.
One in eight 12-15-year-olds said social media brought pressure to look popular all the time, and 29% of those who went online said they had seen something they had found worrying or nasty.
More from Internet safety
The Association of School and College Leaders (ASCL) recently found that most school leaders it surveyed believed children's mental health had suffered as a result of social media in the past year.
The Government has also announced it will introduce a new code of practice setting out minimum expectations on social media companies to try to make the UK "the safest place in the world to be online".