North Korea reported that it has successfully tested a new Hydrogen Bomb on Wednesday. The move is considered to be both surprising and defiant, as no mention of new bomb tests had been mentioned by Kim Jong Un during his New Year speech.

North Korea claimed in the statement that the test came in an effort to expand its relatively small nuclear arsenal in an effort to protect the country from its enemies around the world, such as the United States.

“It is our legal right to protect ourselves from American aggression,” the government statement read.

The test came only months after Kim said that the country is in possession of a new hydrogen bomb.

Hydrogen bombs are much more powerful and much more difficult to make than nuclear bombs. A confirmed test would be far more worrying than North Korea’s existent but modest arsenal of nuclear bombs, and would cause a push for a new round of sanctions to be implemented in the United Nations. The test also likely will worsen the already awful relations between the politically isolated country and its neighbors.

It is to be noted that before the statement was made an an earthquake which ranked as 5 on the richter scale was documented near North Korea’s previous nuclear testing site. The seismic activity is stronger in this quake than during previous nuclear tests which were conducted in  2006, 2009 and 2013.

According to the South Korean news agency Yonhap, the South Korean government issued the following response to the test: “South Korea will cooperate with regional partners to make North Korea pay a price for its hydrogen bomb test. We strongly denounce the North for conducting the fourth nuclear test as the North pushed ahead with it despite repeated warnings by the international community.”

The United Nations Security Council will be holding a special meeting to discuss the recent test, which has garnered significant international worry.