This week, I’m in London to mark an important milestone. Five years ago, leaders from all over the world came together to insist on making family planning a global priority. Together, we made a promise to enable 120 million more women and girls to use modern contraceptives by 2020 with the goal of achieving universal access to contraceptives for everyone, everywhere.

Now, we’re back in the U.K. to celebrate our progress and prepare to meet the challenges ahead. I truly believe the conversation around contraceptives is one of the most important conversations the world will have this year.

I’ve used contraceptives for most of my life, but like a lot of people, I thought of family planning as a personal issue — not a global one. I couldn’t imagine speaking about it publicly.

Everything changed when Bill and I launched our foundation, and I started spending time with women in the world’s poorest places. Everywhere I went, the conversation turned to contraceptives. I met women who were getting pregnant too young, too old, and too often for their bodies to handle. I met women who were desperate not to get pregnant again because they couldn’t afford to feed or care for the children they already had. In Malawi, everyone I met knew someone who had died in pregnancy. In India, I asked a group of women if anyone had lost a child, and every single woman raised her hand.

When I started studying the data, I learned that contraceptives are an essential part of the healthier, more prosperous world we’re all working toward. When a woman has access to contraceptives, she tends to have fewer children. Families can devote more resources to each child’s nutrition, health, and education, setting them up for a better future. Women are freer to work outside the home, earn an income, and contribute to the economy.

Multiply that by millions of families, and it becomes clear why contraceptives are one of the greatest antipoverty innovations the world has ever known — and one of the smartest investments countries can make.

For all of these reasons, I can’t turn my back on the women I meet. They bring up contraceptives because their lives depend on it. And I am committed to making sure their voices are heard. Expanding access to contraceptives is a priority for our foundation. We partner with an incredible network of governments and organizations, many of which are already decades into this work.

Over the past five years, the Family Planning 2020 partnership has made significant gains. We’ve reached tens of millions more women in developing countries with access to contraceptives. And looking ahead, we know the data we’ve collected and the lessons we’ve learned will help us ensure that progress reaches more women in more places.

We also know that our advocacy is needed now more than ever. This is a difficult political climate for family planning. I’m deeply concerned about the White House’s proposed budget cuts to global family planning efforts. If empowering women is more than just rhetoric for the president, he will prove it by protecting this funding.

There are 1.2 billion adolescents in the world today, the largest generation in human history. If we empower them with the right tools — including the tools to prevent teenage pregnancy — these young men and women will unlock unprecedented growth in the world’s poorest countries.

And the stakes will only get higher. The politics of the moment don’t change the fact that the world is at the cusp of a demographic tipping point. There are 1.2 billion adolescents in the world today, the largest generation in human history. If we empower them with the right tools — including the tools to prevent teenage pregnancy — these young men and women will unlock unprecedented growth in the world’s poorest countries. But for this generation to achieve their promise, the family planning community must first keep ours.

That’s why I just announced that our foundation is committing an additional $375 million to this work, to be used over the next three years. This additional funding won’t begin to fill the gap that proposed U.S. budget cuts could create. But it will help build a bridge to the women and girls we have yet to reach.

Alongside our partners, we will prioritize the needs of adolescents and youth. We will work to ensure that women and girls have reliable access to a range of contraceptive options so that they can find one that fits their needs. We will also keep investing in the data to make these programs more effective — especially data on adolescents.

The headway we’ve made over the last five years makes me optimistic about what is possible in the next three. But I also know that the biggest drivers of progress aren’t necessarily in London this week; they’re the women and girls who are walking long miles to health clinics and waiting in long lines for information and contraceptives. They’re inspiring all of us with countless acts of courage and hope.

Now, we must match their determination with our own, until every woman, everywhere has the chance to live the life she deserves.