The South Korean military has launched a special unit to "decapitate" North Korea's leadership, including the country's powerful leader Kim Jong-un, in case a war breaks out in the Korean peninsula.
"What is clear is that every time he conducts a missile launch, a nuclear test, he gets better", McMaster told Baier, "Whether it's a success or failure isn't as important as understanding that over the years he's been learning from failures, improving, and thereby increasing his threat to all of us".
"There are ways to address this problem short of armed conflict, but it is a race because he's getting closer and closer, and there's not much time left".
North Korea has said it will detect even the slightest movement by the brigade and launch retaliatory operations.
Graham expressed confidence in the Trump administration's ability to manage the growing conflict with North Korea.
The F-22s flew into South Korea together in a show of force, and the allies plan to stage simulated attacks on mock North Korean nuclear and missile targets, according to Yonhap.
North Korea reacted angrily on Sunday to the air manoeuvres, accusing the US and South Korea of a "grave military provocation" that will "push the already acute situation on the Korean Peninsula to the brink of nuclear war".
"The stealth fighters which the enemies boast so much of will not escape the fate of a tiger moth", the North Korean commentary said. It launched an advanced intercontinental ballistic missile, the Hwasong-15, that state-controlled media described as the "most powerful ICBM" carrying a "super-large heavy warhead" to unprecedented heights of nearly 4,500 kilometers (2,800 miles).
It is likely the ballistic missile, fired higher than any previous North Korean missile, broke up as it re-entered Earth's atmosphere, the official said. "We're asking China to act in China's interest, as they should, and we believe increasingly that it's in China's urgent interest to do more".
A solid-fuel system for an ICBM would be a significant development and could allow the North Koreans to transport and launch a missile more quickly, compared to a liquid-fuel system that requires lengthy preparation.
"We are in a race to be able to solve this problem", McMaster said.