The UK government has pledged to spend an extra £600m to support family planning programmes in some of the world’s poorest countries.

Most of the money, which will be rolled out between 2020 and 2025, will be given to the UN population fund (UNFPA), which works in 150 countries, including the 46 with the highest rates of maternal deaths and lowest rates of modern contraceptive use.

Some of the money will support women and girls in humanitarian settings, such as in Syria, Yemen and among the Rohingya in Cox’s Bazar, Bangladesh.

Alok Sharma, the international development secretary, said the money was a sign of the UK’s commitment to women and girls’ rights around the world.

“The UK has been at the forefront of global efforts to promote sexual and reproductive health and rights for women and girls living in the world’s poorest countries,” he said.

“This UK aid will help give millions of women and girls control over their bodies, so they can choose if, when and how many children they want. That is a basic right that every woman and girl deserves.”

The money is on top of £200m the UK pledged last year to increase the availability of contraceptives for young women in 27 countries.

The UNFPA has experienced a funding shortfall over the past few years, exacerbated by the US’s decision to defund the agency in 2017, when Donald Trump came to power.

The agency’s executive director, Natalia Kanem, said with the extra money the UK government was “upholding the fundamental principle that reproductive rights are human rights and that no one should be left behind”.

“Every woman and girl should have the chance to live the life she desires – to stay in school, pursue her dream job, and actively contribute to her community and society. Yet for far too many, these rights remain out of reach because they do not have the means to prevent or delay pregnancy.

“To do what is right for these women and girls, and their societies, our ambition must be matched by concrete action and resources.”

The announcement was made at a meeting on universal health coverage, convened at the UN general assembly on Monday. At the meeting, member states committed to protect women’s and children’s health, improve healthcare and ensure no one experienced financial hardship because they had to pay for healthcare.

The UK Department for International Development said the extra money would give more than 20 million women and girls access to family planning services a year. The department calculates that this will prevent more than 5 million unintended pregnancies, 1.5 million unsafe abortions and stop 9,000 women dying from complications in pregnancy and childbirth annually.

UN figures on maternal mortality, published last week, revealed that 295,000 women die each year in childbirth, the vast majority in poorer countries, and mainly from preventable causes.

Simon Cooke, CEO at Marie Stopes International, welcomed the funding announcement. “With the US government and others now reversing at speed from their previous commitments on sexual and reproductive health and rights, it’s heartening to see the UK holding the line to ensure that more women and girls can access essential family planning services.”

According to FP2020, a global partnership to increase women and girls’ access to family planning, an estimated 317 million women and girls in the world’s poorest countries are now using a modern form of contraception, 46 million more than in 2012 when the initiative was launched. However, an estimated 214 million women living in poorer countries who need access to modern contraception do not have it.