North Korean leader Kim Jong-un taunted the US on Wednesday after carrying out an intercontinental ballistic missile test, saying it was a "gift" to "American bastards" on their independence day.

The test of an ICBM on Tuesday was confirmed by US Secretary of State Rex Tillerson, who said it marked "a new escalation of the threat to the world".

It marks a milestone for North Korea's missile programme and heightens concern in Washington about Pyongyang's declared pursuit of a nuclear-tipped missile that can reach the United States.

North Korea's Academy of Defence Science claimed the test of marked the "final step" in creating a "confident and powerful nuclear state that can strike anywhere on Earth".