U.S. President Barack Obama said the world is inspired by the perseverance of those who survived the onslaught.
The genocide was perpetrated by Hutu government and militia forces against ethnic Tutsis. Nearly 1 million people were killed in just 100 days.
"Today, as the United States grieves with the Rwandan people at this moment of remembrance, we are inspired by their spirit as they build a more peaceful and prosperous tomorrow," Obama said in a statement released by the White House. "We look with you to the future and renew our commitment to human rights and the rule of law, to the protection of the vulnerable, and to the prevention of atrocities so that such evil is never repeated."
Secretary of State John Kerry echoed those remarks, saying Americans wanted "to pay tribute to the gracious and determined character of the Rwandan people."
U.N. News said United Nations Secretary-General Ban Ki-moon called on the international community to act with greater haste in the future when genocide is happening.
"Preventing genocide is a shared responsibility. States must uphold their obligations under international law to prevent abuses and protect their populations," Ban said. "Collectively, we must go beyond words and effectively safeguard people at risk. And individually, we must nurture the courage to care -- and the resolve to act. Only by meeting these challenges can we match the resolve of the survivors and truly honor the memory of those who died in Rwanda 19 years ago."