The U.S. has urged North Korea to return to the six-party process and uphold its prior obligations to roll back its nuclear program.

Referring to U.S. President Barack Obama’s State of the Union address, Assistant Secretary of State Phillip Crowley said in a briefing that Washington would step up its sanctions if North Korea continues its nuclear program.

Crowley said North Korea controls its own fate and it has the opportunity to end its isolation.

He also stressed that Washington is currently seeking North Korea’s commitment to return to the six-party talks.