South Korea in live-fire drill after nuclear test
| Updated Sep 04, 2017 at 6:44am
South Korea has conducted a missile drill simulating an attack on the North Korean nuclear site, in response to Pyongyang's sixth test.
The live-fire exercise saw rockets launched from fighter jets and ballistic missiles from the ground.
It came as the US warned that any threat to itself or its allies would be met with a "massive military response".
The North says it tested a hydrogen bomb that can fit on a long-range missile.
Pyongyang has repeatedly defied UN sanctions and international pressure by developing nuclear weapons and testing missiles, and the provocations have only intensified.
In the past two months it has conducted intercontinental ballistic missile tests, sending one over mainland Japan into the Pacific Ocean.
It has also threatened to fire missiles towards the US Pacific territory of Guam.
The UN Security Council is to hold an emergency meeting later on Monday to discuss its response.
Ahead of that meeting, South Korea and Japan's leaders agreed to push for a stronger UN resolution on North Korea, said a South Korean presidential palace spokesman.
The Security Council last imposed sanctions in August, targeting North Korean exports.
The nuclear test prompted an angry response from US President Donald Trump who denounced the test as "hostile" and "dangerous", and called the North a "rogue nation".
He added that the US was considering stopping all trade with any country doing business with North Korea, which relies on China for about 90% of its foreign trade.
Meanwhile, US Defence Secretary James Mattis later told reporters that while the US would respond to any threat "with a massive military response, a response both effective and overwhelming", they were "not looking to the total annihilation of a country, namely North Korea".
A White House statement also said that Washington would defend itself and its allies "using the full range of diplomatic, conventional, and nuclear capabilities at our disposal".
South Korean President Moon Jae-in called the test an "absurd strategic mistake" and urged for the "strongest possible" response, including new UN Security Council sanctions to "completely isolate" the country.
China, meanwhile, also expressed "strong condemnation" and said the state "had ignored the international community's widespread opposition".
South Korean officials said the latest test took place at Punggye-ri nuclear test site in Kilju County.
The "artificial quake" was 9.8 times more powerful than the tremor from the North's fifth test in September 2016, the state weather agency said.
Hydrogen bombs are many times more powerful than an atomic bomb. They use fusion - the merging of atoms - to unleash huge amounts of energy, whereas atomic bombs use nuclear fission, or the splitting of atoms.
Analysts say the North's claims should be treated with caution, but that its nuclear capability is clearly advancing.
SOURCE: BBC News