US President Donald Trump said Thursday that military action against a defiant North Korea after its recent powerful nuclear test was "not inevitable," though he again did not rule it out.
Speaking in a White House news conference alongside the visiting leader of Kuwait, Trump said, "Military action would certainly be an option. Is it inevitable? Nothing's inevitable."
"It would be great if something else could be worked out," he said, while adding that if the US is left with no choice but to attack, "It will be a very sad day for North Korea."
Earlier this month North Korea tested what US officials now believe was a thermonuclear, or hydrogen, bomb -- which could have a much larger impact than a conventional nuclear weapon.
"We are still assessing that test," a senior administration official said on condition of anonymity. "So far there is nothing inconsistent with the North Korean claim that this was a hydrogen bomb, but we don't have a conclusive view on it yet."
Pyongyang says it has developed a miniaturized version of that weapon that could fit atop a long-range missile thought capable of reaching the US mainland.
As president, Trump has alternated between angry and provocative responses to North Korea's fast-developing nuclear and missile programs, and conciliatory remarks about the country and its leader Kim Jong-Un.
The United States is currently pressing China and other world powers to slap an oil embargo on North Korea and sanction Kim's assets.
"It's difficult for an economy to run without access to energy resources and North Korea doesn't drill its own oil, it's the lifeblood of its military," said the senior administration official.
"The amount of pressure that North Korea has been put under economically is still far short of the kind of sanctions that were applied to Iran and also to Iraq."
"There is a long way yet to go to make North Korea feel the kind of pressure that they clearly need to feel in order to change their calculus."
Officials refused to rule out the possibility of military strikes or the United States sending tactical nuclear weapons to South Korea, something that would rile Beijing, North Korea's neighbor and sole major ally.
"We are not kidding when we say all options are on the table," one official said.
Trump on Wednesday said that military action was not his "first choice," but only weeks earlier vowed to rain "fire and fury" on Pyongyang if the North did not stop threatening the United States and its allies.
Trump's top advisers have also issued sharply contrasting statements, sometimes within hours of each other.
While Secretary of State Rex Tillerson has stressed efforts for a diplomatic solution, Defense Secretary Jim Mattis warned that any North Korean aggression against the United States or its allies could bring "massive military retaliation" and even lead to the country's "total annihilation."