North Korea has accused America of a carrying out a "gangster-like" nuclear drill on its shores just days before Donald Trump visits the region as tensions escalated ahead of the trip.

The regime’s news service claimed two B-1B Lancer bombers flew near the Korean peninsula on Thursday and simulated an attack on “major” North Korean targets.

It accused America of “ceaselessly resorting to their frantic nuclear threat and blackmail” to stop the regime’s weapons programme.

The US Air Force confirmed the incident, which it called a “continuous bomber presence mission”, and said it was not in response to any specific event.

The row emerged on the eve of Mr Trump’s 11-day Asia visit that will see him visit Japan, South Korea, China, Vietnam and the Philippines.

Speaking on the White House lawn before the trip, Mr Trump said he had built up “a lot of good will” with leaders in Asia since taking office.

Gathering support for a tougher line on North Korea is a key goal for the US president's longest overseas trip since taking office.