A White House official said that a warning by U.S. Deputy Secretary of State Wendy Sherman of an “unparalleled” scale of response to a nuclear test by North Korea may refer to a “stern response from the international community.”

John Kirby, coordinator for strategic communications at the National Security Council(NSC), made the remark in a press briefing on Thursday in reference to Sherman’s comment in a meeting with her South Korean and Japanese counterparts in Tokyo on Wednesday.

Kirby said that the U.S. wants to sit down with North Korea without preconditions for the denuclearization of the Korean Peninsula, but the North is not responding to the calls for dialogue and is continuing with missile tests, worsening security conditions.

The NSC official said that the U.S. has predicted for months that North Korea is likely to conduct a nuclear test, and it maintains that projection.