WASHINGTON -- The United States has been speaking with "one voice" on North Korea's missile and nuclear threats, leaving no room for confusion over the messages of its president and top diplomat, the State Department said Wednesday.

The US and North Korea have waged a war of words this week following Pyongyang's threats to attack Washington for the United Nations' adoption of tough sanctions against the regime.

US President Donald Trump threated Tuesday to unleash "fire and fury" on Pyongyang if it continued its threats. Hours later, Secretary of State Rex Tillerson said Americans should "sleep well" as the president was simply trying to send a strong message in the kind of language the North Korean leader understands.

"The United States is on the same page. Whether it's the White House, the State Department, the Department of Defense, we are speaking with one voice," State Department spokeswoman Heather Nauert told a regular press briefing.

Citing the sanctions' unanimous adoption, she said, "The United States, along with other nations, condemned North Korea for their destabilizing activities."

Nauert emphasized that foreign ministers attending meetings led by the Association of Southeast Asian Nations earlier this week were united in putting diplomatic pressure on the North.

"(They came) to a joint agreement and a joint statement, and put out a very strong condemnation of North Korea," she said. "We are all singing from the same hymn book." (Yonhap)