Poland introduced a near-total ban on abortions earlier this year.
Belgium says it will provide financial support to women in Poland unable to get an abortion.
Earlier this year, the country introduced a near-total ban on terminations with the only exceptions cases of rape or incest or when the mother's health is in danger.
Doctors who carry out abortions face up to three years in prison.
The decision from Poland's Constitutional Court led to weeks of protest in the country, and warnings from the European Union that Poland must respect fundamental rights.
On Tuesday, which the Women's Global Network for Reproductive Rights has declared as International Safe Abortion Day, the Belgian health minister and equality minister announced €10,000 of funding to the group Abortion Without Borders, which helps people who are unable to access an abortion in Poland.
It is the first country to fund abortions for women in Poland.
Abortion Without Borders is an initiative of six organisations, including the Abortion Support Network, which welcomed the news as “a true act of solidarity”.
“We are thrilled to see our friends in Belgium extend their hands across borders to help people forced by punitive governments to travel for abortion care,” said Mara Clarke, the founder of the Abortion Support Network.
“While the situation for people who need abortions in Poland has been dire since 1990, the ruling made in October 2020 and published in January 2021 has made things even worse.
“The number of people needing our support has doubled, and we are both grateful for this support and hopeful that other countries follow Belgium’s lead.”
Sarah Schlitz, the Belgian junior Minister for Gender Equality, said she and the health minister Frank Vandenbroucke had “taken the decision to send a strong signal” about the need for women’s rights in Poland.
“The grant we are providing will cover the costs of having an abortion in another European country for women who cannot afford it”, she said.
The announcement comes just after days after a Polish anti-choice campaign group pushed for even further criminalisation of people who support others to access an abortion.