North Korean leader Kim Jong-un made a defiant speech at a military parade on Monday night, vowing to ramp up the country's nuclear arsenal.

The parade, to mark the armed forces' founding anniversary, also displayed banned intercontinental ballistic missiles (ICBMs).

In March, North Korea tested its largest-known ICBM for the first time since 2017.

It sparked wide condemnation from the international community.

The US also imposed several sanctions on the country after the test. ICBMs, designed for nuclear arms delivery, extend North Korea's strike range as far as the US mainland.

The parade also featured submarine-launched ballistic missiles in addition to hypersonic missiles.

However, Mr Kim has been undeterred by the condemnation so far.

"We will continue to take steps to strengthen and develop our nation's nuclear capabilities at the fastest pace," he said, adding that their nuclear forces "must be ready" to be exercised anytime, according to a report by the official Korean Central News Agency (KCNA).

North Korea's nuclear weapons were fundamentally a deterrence tool against war but could be used for other means, he said, echoing previous rhetoric that the country would strike back if attacked.

Kim Jong-un wants North Korea to be accepted as a legitimate nuclear state. He also wants the crippling sanctions on his country to be lifted. But he knows neither are likely to happen.

Diplomacy with the US has stalled. President Biden has said he will only look at lifting sanctions if North Korea agrees to give up its nuclear weapons. Kim Jong-un has responded by forging ahead with his nuclear programme, testing an array of increasingly sophisticated weapons.

North Korea has always claimed the reason it has nuclear weapons is to prevent a war. But recently it has started to talk about using these weapons in battle. This was the suggestion in Mr Kim's speech, when he vowed that any military seeking confrontation with North Korea would "cease to exist".

But this show of force is as much about bolstering his popularity as it is his security. North Korea is not just isolated from the international community. It sealed itself off from the world during the pandemic, and its economy is in a bad way. Weapons are one area where Mr Kim can show his people he is making progress.

Parade pictures released by state media show that the Hwasong-17 was among the weapons displayed at the parade. North Korea claimed to have test fired the massive ICBM for the first time in March.

South Korean experts have questioned the success of the test launch.

Typically, Pyongyang showcases its new weapons at its military parades which often feature long processions of tanks, artillery and soldiers.

Monday's military parade was closely watched as North Korea has tested several missiles this year, heightening tensions on the peninsula.

In addition, satellite images have showed North Korea firing up activity at its nuclear testing facility in Punggye-ri in March, stoking fears the country would resume testing nuclear weapons and long-range missiles.

The recent election of South Korea's new president Yoon Suk-yeol, who has voiced a harsher line on North Korea's actions, has frayed relations.

South Korean defence minister Suh Wook earlier this month said the South had the capacity to strike the North's missile launch points - sparking a furious reaction from Pyongyang.

In 2018 Kim Jong-un put in place a moratorium on long-range ballistic missile and nuclear tests, following talks with then US President Donald Trump.

But in 2020, Mr Kim announced he was no longer bound by this promise.

Meanwhile, the Biden administration has repeatedly said it is willing to resume talks without preconditions, but has so far shown little interest in engaging North Korea, which has demanded an end to sanctions.

Mr Biden has instead prioritised relations with South Korea and Japan, and thrown his support behind efforts by the South's outgoing president Moon Jae-in to smooth relations between the two countries.