Ontario's latest attempts to limit cellphone use in classrooms are designed to help students focus on learning, Premier Doug Ford said Monday.

The province's education minister announced new rules Sunday on cellphone and social media use in elementary and high schools.

Ford said his message to students in class is simple: do not use cellphones.

"The teachers want the kids to pay attention, it's as simple as that," Ford said at an unrelated announcement in Ottawa.

"It's not that complicated: Don't use the phones."

Kids in kindergarten to Grade 6 will be required to keep phones on silent and out of sight for the entire school day, unless they get explicit permission from an educator.

Students in Grades 7 and up will see cellphone use banned during class time.

The Progressive Conservative government had asked school boards to come up with their own cellphone policies in 2019, but Education Minister Stephen Lecce said the results were mixed.

Enforcement of the new rules will be left to school staff.

Several teacher unions have said they are skeptical about what the effect of the new rules will be, but will wait to see more details before judging.

The Ontario Secondary School Teachers' Federation said teachers are leery of taking away expensive phones because they would be responsible if they are lost, damaged or stolen.

Ford said he had faith in school staff to support the new rules.

"The principal and the teachers run the school and they're obviously very responsible and they're going to be responsible," Ford said.

He suggested internal polling shows "overwhelming" support from parents for the restrictions.

"It's staggering numbers, the numbers I've seen, with parents supporting the ban because they want their kids to go to school and learn, not to be on social media and fiddling around with their cellphones during class," Ford said.

"Outside of class, all the power to them. You can do whatever you want. But while you're in learning, you've got to learn."

The Toronto District School Board, the country's largest board, said it will look over the details of the provincewide rules and determine how they will affect the development of its own cellphone policy, which was announced at the end of January.

"As part of this policy development process, the TDSB had been planning broad consultations with students, staff, families and experts, along with a review of best practices from around the world, to better understand what will and won't work," Colleen Russell-Rawlins, the board's director of education, wrote in a letter to parents.

"We also want to ensure that any policy has the least negative impact on class participation, attendance, achievement, and the important relationships with educators and principal/vice principals."

Social media websites will also be banned from school devices and school networks as part of the new Ontario rules. Report cards will now include comments on students' distraction levels.

The changes will come into effect in September.