North Korea will continue to test missiles despite international condemnation and increasing military tensions with the US, a senior official has told the BBC in Pyongyang.

"We'll be conducting more missile tests on a weekly, monthly and yearly basis," Vice Foreign Minister Han Song-Ryol told the BBC's John Sudworth.

He said that an "all out war" would result if the US took military action.

Earlier, US Vice-President Mike Pence warned North Korea not to test the US.

He said his country's "era of strategic patience" with North Korea was over.

Mr Pence arrived in Seoul on Sunday hours after North Korea carried out a failed missile launch.

Tensions have been escalating on the peninsula, with heated rhetoric from both North Korea and the US.

Speaking alongside South Korea's acting President Hwang Kyo-ahn, Mr Pence said North Korea should not test US President Donald Trump.

"Just in the past two weeks, the world witnessed the strength and resolve of our new president in actions taken in Syria and Afghanistan," Mr Pence said.

"North Korea would do well not to test his resolve or the strength of the armed forces of the United States in this region."

He reiterated US support for South Korea, telling his host: "We are with you 100%."

At a news conference at the UN on Monday, North Korea's permanent representative Ambassador Kim In-ryong, condemned the US missile strikes in Syria, which targeted an air base after a suspected chemical attack by the government.

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

On Saturday, North Korea showed off its missile capabilities in a grand military parade commemorating the 105th anniversary of the birth of the nation's founding president, Kim Il-sung.

It had widely been expected to carry out a sixth nuclear test, but instead test-fired a missile on Sunday that exploded within seconds of launch.

The state is banned from any missile or nuclear tests by the UN, though it has repeatedly broken those sanctions.

North Korea's aim is to be able to put a nuclear warhead on an intercontinental ballistic missile that can reach targets around the world.

Pyongyang has claimed to have miniaturised nuclear warheads for use on missiles, though experts have cast doubt on that given the lack of evidence.