President Trump warned North Korea on Thursday to stop "behaving badly," saying that while military action is not "inevitable," it remains on the table if the rogue nation continues to ramp up its rapidly expanding nuclear program.

"I would prefer not going the route of the military but it's something certainly that could happen," Trump said during a joint press conference with Amir al-Sabah of Kuwait.

ADVERTISEMENT But he immediately noted his administration's investment in "new and beautiful" weaponry that could be used to quell any potential threat.

"Hopefully, we are not going to have to use it on North Korea. But if we do use it on North Korea, it will be a very sad day for North Korea."

North Korea has repeatedly provoked the U.S. and other countries as it works toward creating a successful nuclear weapon, proving to be one of Trump's biggest foreign policy challenges.

Trump previously warned that North Korea would face "fire and fury" if they continued testing nuclear weapons, leading to saber-rattling and threats to attack the American territory of Guam last month.