Transcript for US, South Korea react to North Korea nuclear test

You want to get to those breaking developments on North Korea this morning there are new concerns another missile tests could be coming as world leaders condemned the rogue nations latest. And largest test yet you don't Iran's regime saint. They successfully detonated hydrogen bomb our chief foreign correspondent Terry landed near the border in Seoul South Korea for us this morning Teri good morning to you. Good morning Paula. This is a huge step forward for North Korea make no mistake about it then as you say look like there's more to come the South Korean government saying they see preparations. For another ballistic missile test by North Korea so they are accelerating the deployment of advanced missile defense systems with the US. Kim Jong-un is sending a message here in its crystal clear he wants a full fledged nuclear capability and right now nothing is slowing him down. This morning a show of force by the South Korean military F fifteen fighter jets on live fire maneuver and missiles launched all simulating an attack on the north. The day after North Korea celebrated its sixth and most alarming nuclear test yet. Kim Jong and the North Korean dictator posed smiling and proud just hours before the blast showing off what Pyongyang's claim is a hydrogen bomb. Vastly more powerful than the ones dropped on Hiroshima and Nagasaki. And capable North Korea says a fitting on the head of an Intercontinental missile. Those some experts say that the fake bomb in the photo. On North Korean state run television people cheered news of the test which triggered a major six point three magnitude earthquake. That's more than ten times the force created by Pyongyang's previous attempt last September. After attending church service Sunday the president was asked directly he plans a military strike on North Korea. Give credit where you attack North Korea. US Defense Secretary Jim Mattis somber and stern. Issuing an ominous warning after meeting with the president. Any threat to the United States or its territories including. Law. Or our allies will be met with a massive. Military response we are not looking to the total annihilation of a country namely North Korea. But as I said that we have many options good news. So president trump also firing off a series of responses via Twitter saying the rogue nations words and actions are very hostile and dangerous to the United States. Hitting not just North Korea but also US allied South Korea for not being tough enough. Their talk of appease met with North Korea will not work he tweeted they only understand one thing. With a series of thirteen launches beginning in February the regime has demonstrated its rapidly developing nuclear capabilities. In a range of possible targets. Prompting president trump to hurl vicious threats in August they will be met. With fire and fury. Like the world has never seen. But Kim Jung on his quickly changing the equation he will soon be able to make his own threats of nuclear fire and fury against the US homeland. Entirely credible. That North Korea nuclear blast came at almost the exact minute that Chinese leaders used on paying. Was opening a major economic conference almost as if Kim Jong-un is taunting the Chinese to the UN Security Council will meet this morning an emergency session. To try to get a handle on this crisis band seems like east hunting many targets Terry Moran thank you.

This transcript has been automatically generated and may not be 100% accurate.