North Korea will continue to test missiles frequently, despite escalating tensions with the US, a senior official has said.

“We'll be conducting more missile tests on a weekly, monthly and yearly basis,” Vice Foreign Minister Han Song-Ryol said.

He told the BBC an “all out war” would happen if America was “reckless enough to use military means”.

The revelations come after US vice president Mike Pence warned "the era of strategic patience is over".

Tensions between the US and North Korea were raised after Pyongyang launched a missile on Sunday morning. The test appeared to fail, with a White House foreign policy adviser saying it was a medium range missile that exploded four to five seconds after it was launched from an eastern port city.

On an unannounced visit to the border between South Korea and its northern neighbour on Monday, Mr Pence made comments suggesting the US would go to extreme measures to force Pyongyang to end its nuclear weapons programme.

He said: “We want to see North Korea abandon its reckless path of the development of nuclear weapons, and also its continual use and testing of ballistic missiles is unacceptable.”

His comments come after US Secretary of State Rex Tillerson visited the border area last month, saying that pre-emptive military action was “on the table”.

Mr Pence called on China, which has long been considered North Korea only significant strategic ally, to use its “extraordinary levers” to persuade the isolationist state to give up its nuclear arms.

In pictures: North Korea marks the Day of the Sun Show all 16 1 /16 In pictures: North Korea marks the Day of the Sun In pictures: North Korea marks the Day of the Sun North Korean women soldiers take part in a military parade in Pyongyang on 15 April AFP/Getty Images In pictures: North Korea marks the Day of the Sun A huge military parade in Pyongyang marks the 105th birth anniversary of Kim Il Sung, the country's late founder and grandfather of current ruler Kim Jong Un AP In pictures: North Korea marks the Day of the Sun North Korean leader Kim Jong-un waves during a military parade on 15 April 2017 AP In pictures: North Korea marks the Day of the Sun North Korean soldiers carry flags and a photo of Kim Il-sung during a military parade in Pyongyang on 15 April AP In pictures: North Korea marks the Day of the Sun Soldiers march across Kim Il Sung Square during a military parade on 15 April AP In pictures: North Korea marks the Day of the Sun What military experts say appears to be a North Korean KN-08 inter-continental ballistic missile is paraded across Kim Il Sung Square during a military parade on 15 April AP In pictures: North Korea marks the Day of the Sun Women wearing traditional Korean dress wave flowers and shout slogans as they pass Kim Jong-Un during a parade in Pyongyang on 15 April AFP/Getty Images In pictures: North Korea marks the Day of the Sun North Korean female soldiers march during a parade for the 'Day of the Sun' festival on Kim Il Sung Square in Pyongyang on 15 April EPA In pictures: North Korea marks the Day of the Sun Military vehicles carry missiles with characters reading 'Pukkuksong' during a military parade marking the 105th birth anniversary of Kim Il-sung in Pyongyang on 15 April 2017 EPA In pictures: North Korea marks the Day of the Sun Attendees carry sheets in the colours of North Korea's national flag during a military parade in Pyongyang on 15 April Reuters In pictures: North Korea marks the Day of the Sun A soldier salutes from atop an armoured vehicle during a military parade in Pyongyang on 15 April Reuters In pictures: North Korea marks the Day of the Sun A North Korean woman cries as she looks towards Kim Jong-un during a parade on 15 April AP In pictures: North Korea marks the Day of the Sun University students carry the national flag and two bronze statues of the late leaders Kim Il-sung and Kim Jong-il during a military parade on 15 April AP In pictures: North Korea marks the Day of the Sun Missiles are driven past Kim Jong-un and other high ranking officials during a military parade marking the Day of the Sun in Pyongyang on 15 April Reuters In pictures: North Korea marks the Day of the Sun North Korean leader Kim Jong-un waves from a balcony during a parade for the 'Day of the Sun' festival in Pyongyang on 15 April 2017 EPA In pictures: North Korea marks the Day of the Sun Missiles are driven past Kim Jong-un and other high ranking officials during a military parade marking the Day of the Sun in Pyongyang on 15 April Reuters

In Washington, Mr Trump was asked if he had a message for North Korean leader Kim Jong-un. He replied: “Gotta behave.”

At a news conference at the UN on Monday, North Korean representative Ambassador Kim In-ryong, criticised recent US missile strikes in Syria, which targeted a military base after a suspected chemical attack.

He said the US was "disturbing global peace and stability and insisting on [a] gangster-like logic".