The US Defense Secretary James Mattis has said any use of nuclear weapons by North Korea would be met with an “effective and overwhelming” response. Mattis is in South Korea, where he has been assuring Seoul it has America’s continuing support.

Speaking after talks at the defense ministry with his South Korean counterpart Han Min-Koo, Mattis told reporters that any attack on the united states, or our allies, will be defeated, and any use of nuclear weapons would be met with a response that would be effective and overwhelming. He also reconfirmed plans to deploy a US missile defense system in South Korea later this year.

Meanwhile, Seoul residents gathered at the headquarters of South Korea’s defense ministry to protest against U.S. Defense Chief’s visit to the country and the planned deployment of the Thaad Terminal high altitude area missile defense system.