Definition: In this task, you need to generate an appropriate title for the given summary of some paragraph. The generated title must be short and should include the main topic of the given text. Your summary should be less than 20 words long.
Input: The US has said its policy of "strategic patience" with North Korea is over and suggested it might decide to take pre-emptive military action.

Rex Tillerson on North Korea: Military action 'an option'