Donald Trump has insisted the North Korean leader Kim Jong-un will not break “the promise he made” about denuclearisation, hours after the secretive communist state fired several short-range missiles from its east coast.

Described as “several projectiles” by the South Korean military, they flew distances ranging from 44 to 124 miles after they were launched off the Hodo peninsula coast, according to South Korea’s joint chiefs of staff.

If it is confirmed that North Korea fired banned ballistic missiles, it would be the first such launch by Pyongyang since November 2017.

Seoul later said it was “very concerned” about the test launch and urged its northern neighbour to resume nuclear negotiations.

Mr Kim has previously promised not to test nuclear weaponry or intercontinental ballistic missiles (ICBMs).

North Korea's pervasive leaders: the Kim portraits Show all 16 1 /16 North Korea's pervasive leaders: the Kim portraits North Korea's pervasive leaders: the Kim portraits In the Democratic People's Republic of North Korea, portraits of former supreme leaders Kim Il Sung and Kim Jong Il are required by law to be hung in the home, the classroom, the factory and all manner of other private and public places Reuters North Korea's pervasive leaders: the Kim portraits In the classroom AFP/Getty North Korea's pervasive leaders: the Kim portraits In the living room AFP/Getty North Korea's pervasive leaders: the Kim portraits In the maternity ward of the hospital Alamy North Korea's pervasive leaders: the Kim portraits On board the ship Reuters North Korea's pervasive leaders: the Kim portraits At the ballot box Mannen av börd North Korea's pervasive leaders: the Kim portraits In the office AFP/Getty North Korea's pervasive leaders: the Kim portraits On the bridegroom Reuters North Korea's pervasive leaders: the Kim portraits On the Pyongyang subway Reuters North Korea's pervasive leaders: the Kim portraits On a government building Reuters North Korea's pervasive leaders: the Kim portraits In the teacher training facility AFP/Getty North Korea's pervasive leaders: the Kim portraits In Kim Il Sung square in Pyongyang Reuters North Korea's pervasive leaders: the Kim portraits In the home AFP/Getty North Korea's pervasive leaders: the Kim portraits At the military parade Reuters North Korea's pervasive leaders: the Kim portraits In the hall Reuters North Korea's pervasive leaders: the Kim portraits At the Chinese border AFP/Getty

Offering his support to his counterpart, Mr Trump tweeted that Mr Kim realised “the great economic potential of North Korea, & will do nothing to interfere or end it.”

He added: “He also knows that I am with him & does not want to break his promise to me. Deal will happen!”

However, earlier this year talks between the pair in the Vietnamese city of Hanoi ended at an impasse over the North’s pursuit of nuclear bombs that can accurately target the US mainland.

North Korea wants widespread sanctions relief in return for disarmament moves that the United States has rejected as insufficient.

In a sign of Pyongyang’s growing frustration, it has recently demanded that the US secretary of state Mike Pompeo be removed from nuclear negotiations and criticised national security adviser John Bolton.

North Korea said last month that it had tested a new type of unspecified “tactical guided weapon.”