A Christian ministry working with persecuted churches said removing North Korea from the US terrorism blacklist gives legitimacy to a country that has the worst religious freedom violation in the world.

"There is no other country in the world where Christians are being persecuted in such a horrible and systematic manner," said Carl Moeller, president/CEO of Open Doors USA, in a statement this week. "Often three generations of Christians are hunted down and killed or placed in prisons.

"Taking North Korea off the terrorism list just prolongs the life of a failing regime by giving it legitimacy," he argued.

The US State Department announced last weekend that it was taking North Korea off its list of state sponsors of terrorism in exchange for reassurances from the rogue regime that it will resume its denuclearisation process and allow international nuclear inspections.

North Korea has been on the blacklist since 1988. Other countries still remaining on the list are Cuba, Syria and Iran.

Moeller believes removing the black mark on North Korea will result in greater hardship for Christians.

Open Doors ranked North Korea as the number one country persecutor of Christians in its 2008 World Watch List. There is absolutely no religious freedom in North Korea, with the government forcing all citizens to worship current leader Kim Jong Il and his deceased father, Kim Il Sung. Being identified as a Christian is the worst crime, and can result in imprisonment, torture or public execution.

According to estimates, there is an underground Christian population of at least 200,000 and possibly as many as 400,000 believers. At least a quarter of the Christians in North Korea are imprisoned for their faith in political prison camps, from which people reportedly rarely get out alive.

"We need to keep the pressure on the United States Government not to forget the terrible status of Christians," the Open Doors president said. "Future dialogue should include freedom of religion and other basic human rights.

"North Korea has not softened its targeting of thousands of Christians one bit," he added. "We must not forget the Christians in North Korea and how the regime of Kim Jong Il keeps them in chains. Please pray with me to have those chains broken."