Tensions between the two neighbors have been raised once more over North Korea’s plans to test a long-range rocket.

South Korea says that the test would violate a ban on ballistic missile tests, and comes just a few weeks after North Korea tested a nuclear weapon for the fourth time. United Nations officials are drawing up new sanctions on Pyongyang as a result of the test, according to the Associated Press.

North Korea Faces "Searing" Consequences If It Launches Missile

Long-range missile launch plans provoke strong opposition

North Korean officials revealed plans to launch a satellite from a rocket between February 8-25. On January 6 Pyongyang claimed to have tested a hydrogen bomb, although that has been contested.

UN Security Council resolutions ban the country from testing ballistic technology, and South Korean and U.S. officials claim that a launch would threaten security in the region.

“We warn that if North Korea proceeds with a long-range missile launch, the international society will ensure that the North pays searing consequences for it as the launch would constitute a grave threat to the Korean Peninsula, the region and the world,” senior South Korean presidential official Cho Tae-yong said in televised remarks.

Chinese officials called for calm and opposed U.S. calls for fresh sanctions.

North Korea’s nuclear program remains shrouded in mystery

The North Korean nuclear program aims to develop missiles capable of striking the U.S. mainland. The last successful long-range missile launch put the first North Korean satellite into orbit, and each test allows scientists to improve their ballistic missiles.

As it stands Pyonygang is thought to have a small number of crude nuclear devices at its disposal, along with a more developed short- and medium-range missile program. Given the secrecy surrounding the programs, little is known about the nuclear and ballistic missile technology that scientists have developed.

As a result experts are unsure whether North Korea has developed nuclear warheads small enough to fit on a missile, or missiles capable of long-range strikes. Recent work on developing missiles has inspired talk of fresh sanctions at the UN.

A similar pattern emerged after a 2012 rocket launch and 2013 nuclear test, with sanctions failing to deter increasingly aggressive rhetoric from North Korea. Pyongyang threatened to fire nuclear missiles at the U.S. and South Korea.