Pompeo last week told nations to "stay committed to applying diplomatic and economic pressure" over the North's nuclear and ballistic missile programmes while calling on the nuclear-armed state to return to talks.

A string of weapons drills by Pyongyang has come during a prolonged hiatus in disarmament talks with the United States and despite recent overtures from Washington offering help to contain the coronavirus pandemic.

In a statement released by the North's official Korean Central News Agency, an unnamed official in charge of negotiations with the US called Pompeo's remarks "ludicrous".

"Listening to Pompeo's ludicrous language made us give up on any hopes for dialogue," the official said, adding: "We will walk our way."

The American diplomat had "unleashed insult at a country with which his president was willing to forge a good relationship", the official continued, referring to Donald Trump's letter sent to North Korean leader Kim Jong Un expressing an intent to cooperate in anti-epidemic efforts.

"It is puzzling who the real commander in chief is in the US," the official said.

The criticism came after the North said it had successfully tested "super-large multiple rocket launchers" on Sunday.

Analysts say the North continues to refine its weapons capabilities more than a year after a summit between Kim and Trump broke down in Vietnam.

Negotiations have since been deadlocked over sanctions relief and what the North would be willing to give up in return.

North Korea is under multiple sets of sanctions from the United Nations, United States and others over its banned weapons programmes.