Blinken told reporters following a meeting with South Korean Foreign Minister Park Jin the United States remained open to dialogue with North Korea but Pyongyang had ignored the calls and instead tested missiles and made preparations to resume nuclear testing for the first time since 2017.
"Until the regime in Pyongyang changes course, we will continue to keep the pressure on," Blinken told reporters, referring to US-led international sanctions on North Korea.
Park said any provocations by North Korea, including a nuclear test, would be met with a united and firm response and urged China to use its influence.
Park said North Korea was at a crossroads - it could go ahead with a nuclear test and isolate itself, or return to diplomacy and dialogue. "I also think China should play a very positive role to persuade North Korea that maintaining peace and stability on the Korean peninsula requires their new thinking," he said.
Park said he and Blinken had agreed on early reactivation of an extended deterrence working group, a policy body dealing with the U.S. nuclear umbrella that protects South Korea. He said the body deals with deployment of strategic assets when necessary, but did not elaborate.