South Korea's president has urged China to help punish Pyongyang for testing the H-bomb
North Korean leader Kim Jong-un sparked international fury last week by completing the nuclear test, in addition to issuing a chilling statement claiming "they were are the brink of war".
South Korea's president Park Geun-hye has now urged China, who is North Korea's only major ally, to help punish the rouge nation for its continued power demonstration.
The request comes after Seoul claimed North Korea had dropped leaflets across the border describing their government as "mad dogs".
South Korea, the United States and others are pushing hard to impose fresh sanctions and other punitive measures on the North Korean dictator.
Diplomats at a UN Security Council emergency session last week pledged to swiftly pursue new sanctions.
However China, as veto-wielding permanent member of the Security Council, is seen as key to imposing those sanctions.
On Wednesday, Park said that South Korea would push as hard as it can for strong sanctions.
She said: "Holding the hands of someone in a difficult situation is the mark of the best partner."
The request comes after Seoul claimed North Korea had dropped leaflets across the border
North Korean leader Kim Jong-un risks facing global sanctions
Holding the hands of someone in a difficult situation is the mark of the best partner
South Korea's president Park Geun-hye
Beijing is seen as reluctant to clamp down on the North because of fears that a toppled government in Pyongyang would lead to millions of desperate North Koreans flooding across the border to China.
Since Friday, South Korea has been blasting anti-Pyongyang propaganda from huge speakers along the border, and the North is using speakers of its own in an attempt to keep its soldiers from hearing the South Korean messages.
Park said South Korea will continue its loudspeaker campaign, calling it "the surest and most effective psychological warfare tool".
Just days after North Korea heightened global tensions with their H-bomb revelation, the US Nazy announced a new missile defence "capable of destroying ballistic missile targets".
China is seen as a key player to enforce sanctions against Pyongyang
The Pentagon revealed the upgrade to the latest Baseline 9.C1 version of its Aegis missile defence system in response to the growing threat.
Spokesman Jim Sheridan said the latest upgrade can destroy air and ballistic missile targets simultaneously.
He said: "The Aegis Combat System Baseline 9.C1 offers unprecedented capabilities, including simultaneous air and ballistic missile defence (BMD).
"The BMD capabilities of Baseline 9.C1 are also present in Aegis Ashore, the ground-based missile defence program that is the second phase of the US Phased Adaptive Approach to protect Europe from ballistic missile attack."