Secretary of State Rex Tillerson said Friday that taking military action against North Korea was "an option on the table," in perhaps the clearest indication yet that the new White House has lost patience with diplomacy and is prepared to aggressively confront North Korea’s nuclear threat.

Tillerson made the comments during a news conference in Seoul after visiting the tense buffer zone between rivals North and South Korea, the world’s most heavily armed border. He said that the "policy of strategic patience has ended" and that the United States was considering a range of measures aimed at persuading North Korea to abandon its nuclear ambitions: military, diplomatic and economic.

"Certainly we do not want to, for things to get to military conflict," Tillerson said: "(But if North Korea) elevates the threat of their weapons program to a level that we believe requires action, then, that option's on the table."

Tillerson is on a tour this week of China, Japan and South Korea. He vowed Thursday to take a "different approach" to North Korea after saying that 20 years of "diplomatic and other efforts" had failed to dissuade Pyongyang from developing its nuclear program. Previous U.S. administrations have held the threat of military action over North Korea in response to nuclear tests or missile launches. Tillerson's remarks go much further in stating that using the military is a real possibility.

"North Korea must understand that the only path to a secure, economic propitious future is to abandon its development of nuclear weapons, ballistic missiles and other weapons of mass destruction," Tillerson said. He called on China, one of the reclusive communist nation's only allies, to refrain from economic retaliations against South Korea for deploying an advanced U.S. missile defense system — known as THAAD —on its soil because of threats from Pyongyang.

Beijing has curbed travel to South Korea and is actively targeting its companies that operate on mainland China with onerous restrictions because of the missile system.