The Prime Minister has appointed what is thought to be the world's first Minister for Suicide Prevention in a bid to cut the number of people taking their own lives.
Health Minister Jackie Doyle-Price will lead the national effort and try to end the stigma which stops people from seeking help, Theresa May announced as she marked World Mental Health Day.
Around 4,500 people take their lives every year in England and suicide remains the leading cause of death among men under the age of 45.
The Prime Minister has also pledged up to £1.8 million to ensure the Samaritans' helpline remains free for the next four years, to help those most in need.
READ: World Mental Health Day is shining a light on the wellbeing of young people
Labour said a focus on suicide prevention was "long overdue" and warned a lack of funding had forced people to wait months for treatment in some areas.
Speaking at a reception to mark World Mental Health Day, Mrs May is expected to say: "When I first became Prime Minister, I stood on the steps of Downing Street and pledged to fight the burning injustices in our society.
"There are few greater examples than the injustices facing those with mental health conditions. But together we can change that.
"We can end the stigma that has forced too many to suffer in silence. We can prevent the tragedy of suicide taking too many lives.
"And we can give the mental wellbeing of our children the priority it so profoundly deserves."
The Prime Minister will also say that "parity of care" is a priority of the NHS long-term plan, which will include "record investment" in mental health.
Ms Doyle-Price, now Minister for Mental Health, Inequalities and Suicide Prevention, will ensure every local area has effective plans in place to stop unnecessary deaths and investigate how technology can help identify those most at risk.
The Yorkshire Post says: Cry for help from young. Ongoing crisis in mental health
She said: "I understand how tragic, devastating and long-lasting the effect of suicide can be on families and communities.
"In my time as health minister I have met many people who have been bereaved bysuicide and their stories of pain and loss will stay with me for a long time.
"It's these people who need to be at the heart of what we do and I welcome this opportunity to work closely with them, as well as experts, to oversee a cross-Government suicide prevention plan, making their sure their views are always heard."
Health Secretary Matt Hancock said: "We're already making progress when it comes tosuicide prevention, the suicide rate is at its lowest for seven years.
"But we need to do more to challenge the stigma that people with mental ill-health face and make sure they feel they can reach out for help.
"I am delighted we are appointing Jackie Doyle-Price as our dedicated Minister forSuicide Prevention, and I know she will make a real difference.
"Every suicide is a preventable death and we are determined to do everything we can to tackle the tragedy of suicide."
The Government has also reasserted its commitment to tackling mental health among young people.
New mental health support teams will work with schools to ensure young people get the help they need.
Schools will also be given help to measure their students' health, including their mental wellbeing, under the plans.
A new report will be published into the state of young people's mental health every year on World Mental Health Day, it said.
The second day of the Global Ministerial Mental Health Summit in London takes place on Wednesday.
Harsh lessons in distress - students tell of mental health struggles at university
Labour has had a shadow cabinet minister for mental health since 2015 and the party has pledged to increase spending on services and protect budgets.
The current shadow minister, Barbara Keeley, said: "A focus on suicide prevention is long overdue given the appalling increase in suicide rates since 2010, particularly among young people, but it also needs proper funding of front line services.
"Mental health services are still being underfunded by the Conservative government, with one in 10 CCGs (Clinical Commissioning Groups) failing to meet the mental health investment standard in the last year - that is leading to adults having to wait as many as four months for treatment in certain areas, while one in four children are being rejected for treatment after referral."