US President Donald Trump said the United States sends its "heartfelt condolences" and stands by ready to help.
"138 people have been killed in Sri Lanka, with more than 600 badly injured, in a terrorist attack on churches and hotels," President Trump wrote. "The United States offers heartfelt condolences to the great people of Sri Lanka. We stand ready to help!"
Canadian Prime Minister Justin Trudeau said the attacks were "absolutely horrific" and "heinous."
"Absolutely horrific news from Sri Lanka. Canada strongly condemns the heinous attacks on Christians at churches and hotels. Our hearts & thoughts are with the families & loved ones of those killed and all those injured," Trudeau wrote on Twitter.
Pope Francis condemned the attacks during his Easter Sunday speech in Rome, Italy. He offered “heartfelt closeness to the Christian community, attacked while gathered in prayer, and to all the victims of such a cruel act of violence.”
"I entrust to the Lord all who so tragically died, and I pray for the wounded and all those who suffer because of this traumatic event," Francis said during his speech.
He also called for more attention and diligence in managing world conflicts in order to avoid future acts of violence. Pope Francis also referenced conflicts in Yemen and Libya during his speech to approximately 70,000 people.
"Now is instead the time for a renewed commitment for a political solution able to respond to people's legitimate hopes for freedom, peace and justice, confront the humanitarian crisis and favor the secure reentry of the homeless, along with all those who have taken refuge in neighboring countries, especially Lebanon and Jordan," he said.
New York Governor Andrew Cuomo also offered his condolences and called for state police to increase security measures at places of worship.
"During these troubling times, we will not be intimidated by cowardly acts of violence and will continue to do everything in our power to ensure the safety of all New Yorkers," Cuomo said in a statement.
Pakistan's Prime Minister Imran Khan said his country "stands in complete solidarity with Sri Lanka in their hour of grief."
"Strongly condemn the horrific terrorist attack in Sri Lanka on Easter Sunday resulting in precious lives lost & hundreds injured. My profound condolences go to our Sri Lankan brethren. Pakistan stands in complete solidarity with Sri Lanka in their hour of grief," Khan wrote.
Nancy Pelosi called the attacks "heartbreaking."
She wrote: "Today's heartbreaking attacks in Sri Lanka come as the country has worked hard to build a common future after years of war. Our thoughts are with the injured & the families of those killed in today's Easter Sunday attacks."
In 1983, Sri Lanka went through a 25-year civil war between rebels and the country's government.
Former US President Barack Obama said the events in Sri Lanka are "an attack on humanity."
"The attacks on tourists and Easter worshippers in Sri Lanka are an attack on humanity. On a day devoted to love, redemption, and renewal, we pray for the victims and stand with the people of Sri Lanka," Obama wrote on Twitter.
US Senator and 2020 presidential candidate Elizabeth Warren said she was "heartsick" for the victims of the attacks.
Warren also called the events "an act of great evil" on Twitter.
She wrote: "I'm heartsick for the victims of today's terrorist attacks in Sri Lanka. Hundreds have been killed and wounded. To slaughter worshippers at church during Easter service is an act of great evil. My thoughts and my prayers are with the victims and their loved ones."