Following US President Joe Biden's denunciation of North Korea's firing of two missiles as part of its military tests, a senior official in Pyongyang described it as a "promise" and a "provocation"

"Such comments by the President of the United States are a clear violation of our State's right to self-defence and provocation," said Ri Byung Chol, who oversaw the rocket launch in a statement.

North Korea has declared that what it launched in the Sea of Japan was a new "guided tactical projectile."

Japanese Prime Minister Yoshihide Suga considered the two missiles launched from North Korea's east coast to be "Balstian," the type of missiles that Pyongyang is prohibited from developing under a United Nations Security Council resolution.

It should be noted that Biden warned that the United States would "respond to any" escalation, "calling the firing of the rockets a" violation "of Security Council resolutions.

In his statement, Ri said that the North expressed "deep fear at the error of the United States Chief Executive in considering systematic missile tests, which are the exercise of our country's right to self-defence, as a violation of the United Nations resolution."

The Korean official regretted that Biden had revealed his "intrepid hostility," expressing the belief that "the US administration has clearly taken its first step wrongly."

"If the United States continues its reckless comments without thinking about the results, then it can be met with something that is not good," he added, warning that North Korea stands ready to continue to strengthen its military strength.