Secretary of State Rex Tillerson is planning to press China's leaders about restraining North Korea's nuclear program in his first mission to Asia. China has confronted the Trump adminstration regarding the decision to deploy the Thaad antimissile system in South Korea. Beijing fears that the advancement will pose a challenge to regional stability. The U.S. is pushing forth the message that it will respond to North Korea's military advancements. It remains unclear how Tillerson will deliver the message to China.