Savita Halappanavar died in 2012 from a septic miscarriage after she was refused a termination in an Irish hospital, sparking a huge outcry that helped galvanize the campaign to legalize abortion in the Catholic country.

In an open letter, Watson credited the 31-year-old dentist with helping to bring about a "historic feminist victory that emboldens the fight for reproductive justice everywhere".

"There is still more work to be done. Free, safe, legal and local abortion care is needed across the globe," Watson wrote in the letter, published on the fashion website Porter.

Abortion is highly restricted in 125 countries, affecting 42 percent of women globally, the majority of them in the developing world, according to research published this year by think-tank the Guttmacher Institute.

A total ban on abortion exists in 26 countries.

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Irish voters backed to change a law that gave an unborn child and its mother equal rights to life by two-to-one in a referendum in May this year.

For decades, the law forced more than 3,000 women to travel to Britain each year for terminations.

The Irish government is expected to pass laws allowing abortions with no restriction up to 12 weeks into a pregnancy by the end of the year.

Watson, famous for her roles in the Harry Potter series of films, first spoke out in favor of gender equality as a UN Women Goodwill Ambassador in 2014.

Earlier this year she donated 1 million pounds to the UK Justice and Equality Fund, a crowdfunding campaign to fight sexual harassment.