"We strongly condemn Sunday's attack on innocent people at two churches in Lahore, and we extend our deepest sympathies and condolences to the families of the victims," State Department Spokesperson Jen Psaki said on Monday.
"The United States stands in solidarity with the people and Government of Pakistan in confronting this type of extremist violence," she said.
"We support the right of every person to practice religion without fear of intimidation, death, coercion, or any form of reprisal. This is a basic human right both in Pakistan and throughout the world," Psaki said.
At least 15 people were killed and over 80 others injured when Taliban suicide bombers attacked two packed churches during the Sunday mass in Lahore's biggest Christian colony, one of the worst attacks on the minority community in recent times.
The attacks later triggered mob violence in which two suspected militants were lynched and then set ablaze, resulting in their deaths.