Liberia and Senegal have pledged to reform their laws so that women can confer citizenship on their children.
The West African nations are currently among at least 30 countries that let only fathers pass their citizenship to children from marriages with a foreigner.
Others include the Bahamas, Iran, Malaysia, Saudi Arabia and Qatar.
The U.N. refugee agency says discrimination against women has contributed to the estimated 12 million stateless people around the world.
Liberia and Senegal made the pledge Thursday at a ministerial meeting in Geneva marking the 50th anniversary of the 1961 Convention on the Reduction of Statelessness.
U.S. Secretary of State Hillary Rodham Clinton urged diplomats Wednesday to amend discriminatory citizenship rules.