North Korea warned on Sunday that the United States will face a "very grave situation" as President Joe Biden made a "big blunder" by calling the North a serious threat in his first policy speech to Congress.

Kwon Jong-gun, director general of the Department of U.S. Affairs of the North's Foreign Ministry, issued the warning in a statement carried by the North's official Korean Central News Agency on Sunday.

The statement comes after the White House said U.S. officials had completed a months-long review of North Korea policy. It also comes after Biden pledged in his first congressional address last week to work with allies to address "serious threats" from the North and Iran through "diplomacy and stern deterrence."

Kwon said that now that the keynote of the United States’ new North Korea policy has become clear, the North will be compelled to press for corresponding measures.

He also downplayed "diplomacy" and "stern deterrence" which Biden pledged to use to address threats from the North, calling them "intolerable."

Kwon said that United States' talk of diplomacy is aimed at covering up its hostile acts, and its deterrence is just a means for posing nuclear threats to North Korea.

In a separate statement, the North's Foreign Ministry also slammed Washington for criticizing its human rights record, saying it amounts to insulting the "dignity of the North's supreme leadership."