.- There must be “some sort of religious freedom” in North Korea before a papal visit to Pyongyang, a South Korean bishop said Thursday.

Bishop Yoo Heung Sik of Daejeon, who has made multiple trips to North Korea on behalf of the South Korean Bishops Conference, originally welcomed the news that South Korea’s President Moon Jae-in and Chairman Kim Jong Un had discussed inviting Pope Francis to visit the DPRK during their meeting in late-September.

“It would be a giant step forward for peace on the Korean peninsula,” Bishop Yoo told reporters at an Oct. 11 Vatican press conference.

The bishop cautioned that “in order for him [Pope Francis] to go there, some things in North Korea should change.”

“For example, there are no priests in North Korea,” he continued.

Pyongyang was once referred to as the “Jerusalem of the East” and was considered a center of Christianity in Northeast Asia.

Just before the Korean War broke in 1950, most of the priests in North Korea were captured, killed, or disappeared, according to the Korean Bishops Conference. The beatification process has begun for 40 monks and sisters of Tokwon Benedictine Abbey who were martyred by the Communists.

In 1988, the “Korean Catholic Association” created by the Communist government registered 800 members. This association is not recognized by the Vatican, but is one of three state-sponsored churches that operate in North Korea under strict supervision of the Communist authorities.

Mass is occasionally celebrated in Pyongyang's Changchung Cathedral when a foreign priest is on an official visit to the country, but on Sundays a liturgy of the word is usually celebrated by state-appointed layperson. The Catholic See of Pyongyang is vacant and the last bishop was appointed in March 1944. There are no native Catholic clerics in North Korea.

North Korea has consistently been ranked the worst country for persecution of Christians by Open Doors. Christians within the atheist state have faced arrest, re-education in labor camps, or, in some cases, execution for their faith.

A United Nations investigation in 2014 produced a 372-page report that documented crimes against humanity, including execution, enslavement, torture, imprisonment, forced abortions, and knowingly causing prolonged starvation.

The U.S. State Department estimates that there are currently an estimated 80,000 to 120,000 people in North Korea’s six political prison camps.

On June 12, President Donald Trump and Chairman Kim Jong Un met in Singapore and signed a joint-statement making commitments “to build a lasting and stable peace regime on the Korean Peninsula.”

Human rights were “discussed relatively briefly compared to denuclearization,” according to President Trump, who also said that North Korea’s abduction of Japanese citizens and the regime’s persecution of Christians were brought up in his 45 minute conversation with Kim.

Earlier this week, U.S. Secretary of State Mike Pompeo met with Kim Jong Un in North Korea to discuss details for a second summit between President Trump and Chairman Kim to continue negotiation of the denuclearization of the Korean peninsula, according to the State Department.

If President Trump helps Koreans achieve “a peaceful, united Korea” then “he will become an American president who makes history working for world peace,” Bishop Yoo told CNA.

The South Korean bishop said that the de-escalation of nuclear tensions on the Korean Peninsula this year is “thanks to the Holy Spirit.”