World leaders have lined up to condemn the blast, which was North Korea's second this year and likely it's most powerful to date. South Korea believes Kim Jong Un is preparing to hit the button on another test.
"We assess that (North Korea) is prepared for a nuclear test in another shaft," Defense Minister Han Min-koo told lawmakers Friday.
His spokesman Moon Sang-gyun, said Monday if another nuclear test happened, it could come from a second or third site at Punggye-ri, where Friday's test took place.
South Korea is also discussing plans to resume propaganda broadcasts on the border from sometime in November, he added.
South Korean Foreign Minister Yun Byung-se said over the weekend that North Korea's nuclear capability had grown to a "considerable level" and tougher sanctions and greater pressure are needed.
The country's military also said it was implementing a new system which will allow them to "punish and retaliate" against North Korea's leadership if it endangers the country with nuclear weapons.
But, in the diplomatic realm, there's little consensus on what the international community can do .
Sung Kim, the US special envoy to North Korea said the UN Security Council along with Japan, South Korea and the United States are examining additional unilateral measures. The Security Council is due to meet Friday.
North Korea shrugged off the threat of additional sanctions in typical fashion.
"The Obama administration running around and talking about meaningless sanctions until today is highly laughable," state media said Sunday.
"We will continue to strengthen our nuclear power in quality and quantity to protect our dignity and the right to live as well as to ensure genuine peace from the increasing threat of a nuclear war by the United States."
Concern has been growing
that the country is testing weapons at an unprecedented pace this year, continuing to improve its nuclear and missile capabilities. However, it has yet to pair the two successfully.
North Korea was hit with the strongest set of sanctions yet in March
which included the prohibition of supplying aviation fuel, including rocket fuel, and the sale of small arms, to Pyongyang.
And in July, the Obama administration hit Kim Jong Un and 10 other regime officials with personal sanctions for their alleged complicity in human rights abuses
against the North Korean people.
China, regarded as North Korea's only ally, could be pressed to take the strongest possible action by blocking the transportation of fuel and oil but that could have grave consequences for the general population.
The country's Foreign Ministry spokesperson Monday dismissed comments by U.S. Secretary of Defense Ash Carter that China bears "great responsibility" for North Korea's latest nuclear test.
"The essence of the issue is the conflict between the DPRK and the US," said Hua Chunying, Chinese Foreign Ministry spokeswoman, using country's official name.
"The US side should review developments of the issue, and carefully think about pragmatic and effective solutions."