Story highlights Tillerson is visiting Japan, South Korea and China on his first official trip to Asia

He has previously criticized US policy on North Korea

Seoul (CNN) The US would consider military action against North Korea if it was provoked, Secretary of State Rex Tillerson said Friday.

Speaking in Seoul at a joint press conference with South Korean Foreign Minister Yun Byung-se, Tillerson said Washington's policy of "strategic patience" had ended.

"Certainly, we do not want things to get to a military conflict ... but obviously, if North Korea takes actions that threatens the South Korean forces or our own forces, then that would be met with an appropriate response," he said, in response to a question from CNN.

"If they elevate the threat of their weapons program to a level that we believe that requires action, that option is on the table," Tillerson added.

Later Friday morning, President Donald Trump denounced North Korea, tweeting, "North Korea is behaving very badly. They have been 'playing' the United States for years. China has done little to help!"