A study released by the Pew Research Center revealed that Christians are actively harassed in more countries around the globe than any other religious group.

The persecution of Christians increased dramatically from 2015 to 2016, with the number of countries in which Christians are harassed—either by governments or social groups—rising from 128 to 144 in the space of just one year, Pew found.

Among all nations, China had the highest levels of government restrictions on religion, while India had the highest levels of social hostilities involving religion. “Both countries had the highest levels of restrictions in these respective categories, not only among the 25 most populous countries but also in the world at large,” Pew said.

As a group, Middle Eastern and Northern African governments were the worst violators of religious liberty on a regional level, followed by the Asia-Pacific region, Europe, Sub-Saharan Africa, and the Americas, Pew found.

In the Western Hemisphere, the country with the most restrictive policies toward religion continues to be Cuba, despite promises to the contrary. Broad-ranging detentions of Christians continue to take place in the communist nation, the study found, such as when Cuban officials arrested 200 members of Emmanuel Church in Santiago de Cuba and demolished the church in 2016.

The United States is gearing up for an unprecedented global summit on religious liberty to be held in late July. Secretary of State Mike Pompeo called religious freedom the “most fundamental of human rights” and declared that “the United States will not stand by as spectators” while people around the world are persecuted for their religious beliefs.

“Most countries around the world have some form of restrictions on religion — whether it is through laws that limit actions like public preaching or conversion, or actions that can include detaining, displacing or assaulting members of religious groups,” the Pew report declared. “A subset of countries, however, has particularly high levels of government restrictions on religion.”

Pompeo has called religious freedom “a right belonging to every individual on the globe” and said the U.S. “stands with those who yearn for religious liberty.”

The year 2018 marks the 20th anniversary of the passage of the Religious Freedom Act, which singles out religious liberty as an important U.S. foreign policy. The Act created within the State Department the ambassador-at-large for international religious freedom, a post held since February by Samuel D. Brownback.

“Religious freedom was vital to America’s beginning,” Pompeo said. “Defending it is critical to our future.”