The U.S is to tighten sanctions on North Korea and step up diplomatic moves aimed at pressuring the country to end its nuclear and missile programmes.
President Donald Trump’s new strategy was announced after a special meeting with US senators.
Earlier, the top US commander in the Pacific defended the deployment of an advanced missile defence system in South Korea.
Tensions have risen amid fears the North is planning new weapons tests.
“The United States seeks stability and the peaceful denuclearization of the Korean peninsula.”
“We remain open to negotiations towards that goal. However, we remain prepared to defend ourselves and our allies.” said a joint statement issued by Secretary of State Rex Tillerson, Defense Secretary Jim Mattis and Director of National Intelligence Dan Coats.