North Korea's ballistic missile test early Saturday was in "open defiance" of the global community, and the risk to the USA will not be tolerated, National Security Adviser H.R. McMaster said Sunday.
The conversation followed another North Korean missile test-launch on Saturday, which Washington and Seoul said was unsuccessful.
"The threat of a North Korean nuclear attack on Seoul or Tokyo is real, and it is likely only a matter of time before North Korea develops the capability to strike the U.S. mainland".
Seoul and the United States say the sole objective of THAAD is to guard against North Korean missiles. "He had military exercises", Petras said.
Pyongyang's ballistic missile tests have been banned by the United Nations, as they are considered to be part a North Korean program aimed at building a nuclear-capable missile.
A South Korean military official also said without elaborating that the launch was believed to be a failure.The official could not immediately confirm how far the missile flew or whether it had exploded shortly after launch.
That means, McMaster said, working to enforce current United Nations sanctions and perhaps ratcheting them up.
US President Donald Trump told Reuters in an interview on Thursday that North Korea was his biggest global challenge and a "major, major conflict" with it was possible over its nuclear and ballistic missile programs.
Since meeting with China's President Xi Jinping at his Mar-a-Lago estate in Florida April 6-7, Trump has set aside his campaign threats to impose tariffs on Chinese imports and declare Beijing a currency manipulator.
Trump then took to Twitter, saying North Korea "disrespected" China's wishes.
"We have a situation that we just can not let - we can not let what's been going on for a long period of years continue", Trump said.
Partially as a show of force, the USA has been participating in drills with South Korea and Japan in waters around the Korean Peninsula. "Something that's ready to go could be taken from the larger package and expedited".
Trump and North Korean leader Kim Jong-Un are locked in an ever-tighter spiral of threat, counter-threat, and escalating military preparedness. "The key to solving the nuclear issue on the peninsula does not lie in the hands of the Chinese side", Wang said.
"In a nutshell, DPRK have already declared not to attend any type of talks which would discuss its nuclear abandonment, nuclear disbandment", Kim In Ryong said. There is still uncertainty surrounding some of the latest missile launches. This was not a nuclear test, which he was expected to do three days ago.
When asked, Mr Trump said Mr Kim will eventually develop better missiles, and "we can't allow it to happen".
As is evident from Trump's tweets, he has put a lot of faith in China in their joint efforts to keep North Korea in check.
The deployment has drawn protests from China, which says the powerful radar, which can penetrate its territory, will undermine regional security, and from local residents anxious they will be a target for North Korean missiles.