Efforts have focused on on providing injectable contraceptives in countries like Kenya. Photo: Thinkstock
By Jane Dreaper Health correspondent, BBC News
Plans to get contraceptives to millions more women in the world's poorest countries are behind track, a report by campaigners and donors warns.
The goal is for 120 million extra women to have access to contraceptives by 2020. But so far around 25 million more women are using pills or devices such as implants.
Leading campaigner Melinda Gates told BBC News she was "very optimistic" the target would be met. The goal was agreed at a summit about family planning, which was held in London in 2012.
Donor governments including the US and UK, drug companies and organisations such as the Bill and Melinda Gates Foundation made funding commitments worth a total of $2.6bn at the meeting.
A progress report - called FP2020 - suggests that in the past year alone, the effort has averted 80 million unintended pregnancies.
But around 10 million fewer women than planned are currently being reached.
The data was due to have been released at a conference about family planning in Indonesia this week - but it was cancelled due to volcanic activity there.
On behalf of the couple's foundation, Melinda Gates pledged an extra $120m of funding for family planning. The hope is that this move will encourage governments and other organisations to step up their efforts.
Melinda Gates told me: "There's quite a climb to go but I'm very optimistic.We now have data on family planning which we didn't have previously. I now have a report on my desk about it every six months.
"The updates in this area used to be every five or six years.We also have very specific indicators now - about quality and checking that women are voluntarily accessing family planning services. That means you can see where we need to pinpoint where we need to go, and see where we are off track."
She added: "In global health, there is always time where you have to lay groundwork before progress accelerates. I think we're on the verge of that now."
Melinda Gates praised countries which had found "culturally appropriate" responses to providing contraception.
This includes Niger, which has run 1,000 'husband schools' where men are educated about the value of contraceptives for their wives. I asked how she resolved any potential conflicts between her Catholic faith and her work to improve family planning.
She said: "The place where the Catholic Church and I agree wholeheartedly is that we need to make life better for poorer women around the world.
"Bill and I feel we should live in a more equitable world, and one of the ways to do that is to allow women to space the birth of their children. We work in deep partnership with Catholic relief services on many different areas, so that's how I resolve those two issues."
The renewed effort to widen access to contraceptives will focus on women in cities in 69 countries across Asia and Africa.
There has been progress in Kenya, which has concentrated on providing injectable contraceptives, and in Indonesia, which is upgrading thousands of family planning clinics.
The UK's Department for International Development (DfID) is the second biggest donor to the family planning campaign. Its head of human development, Jane Edmondson, said: "We can still get on course to meet this target.
"It means prioritising and budgeting for these commitments, and coming up with the funds. "This is also about tackling discrimination, outlining our support publicly and shifting social expectations about empowering women and girls."