Sanctions, military drills, and global condemnation greeted the launch of Pyongyang's largest-ever intercontinental ballistic missile (ICBM) Thursday, but for Kim the censure is worth it.

He's playing a defensive game, analysts say, and his weapons programmes, far from being a bargaining chip, are an end in themselves: they help guarantee the Kim regime will stay in power.

"They cannot make it any more obvious that they consider it important for the survival of the regime," said Mason Richey, an associate professor at Hankuk University of Foreign Studies, referring to the state media messaging around the launch.

From personally overseeing the test-firing to trumpeting his country's new "formidable military and technical capabilities", Kim was front and centre, making a simple point.

"It's a not very subtle way of saying this deterrent value is important for the country, the regime, and for Kim Jong Un personally," Richey said.

In his customary black leather jacket and sunglasses, Kim is valorised in dramatic state media photos and video showing the missile blasting off in a blaze of fire and smoke.

"His authorisation of the test -- as well as him overseeing the launch in person -- means that there is no turning back now," said Ahn Chan-il, a North Korean studies scholar.

After five years of diplomacy by outgoing South Korean President Moon Jae-in, Kim's ICBM launch this week sends a final, decisive message that talks were "totally useless", he said.

When South Korea's new, hawkish President-elect Yoon Suk-yeol takes office, he will have to deal with a more confident Kim, who will argue his weapons give him "total control" of issues of peace and security on the Korean peninsula.

- 'Don't invade' -

There is no hidden message behind Pyongyang's development of ever more powerful strategic weapons, Jeffrey Lewis of the Middlebury Institute for International Studies wrote in a Twitter thread.

"The message was: 'I will be able to nuke the crap out of you if you invade. So don't.'"

Having watched what happened in Iraq and Libya, Kim has no plans to use his weapons development to secure talks or concessions from the United States, he said.

"Kim Jong Un doesn't want to end up like Saddam or Gaddafi. Unlike them, he's not going to disarm. He's going to continue to develop the ability to nuke the crap out of us if we attempt to invade."

Now that Pyongyang has officially jettisoned its self-imposed moratorium on long-range and nuclear testing -- in place since Kim embarked on failed talks with then-US president Donald Trump in 2018 -- it is likely to conduct ever more powerful weapons tests.

These will be met, in turn, with sanctions and ramped up military drills from the United States and South Korea -- which will be met with more tests, analysts predict.

North Korea's weapons technology has advanced "very rapidly" to the point that, unlike previous escalatory cycles, existing mechanisms to contain the country may no longer work, some warned.

"It is impossible for the US to prevent North Korea from advancing its nuclear and missile capabilities by implementing sanctions alone," said Cheong Seong-chang of the Centre for North Korea Studies at the Sejong Institute.

He said North Korea would likely launch a military reconnaissance satellite and conduct tactical nuclear warhead tests later this year.

"Now is the time for the United States to seriously consider the issue of the nuclear possession of South Korea and Japan," he added.

- 'Buckle up' -

All of this means, "buckle up, essentially", said Soo Kim, a RAND Corporation policy analyst and former CIA analyst, predicting a bumpy ride on the peninsula after hawkish Yoon takes office.

Yoon has already called the ICBM launch a "provocation" and warned Kim he would not benefit from such tests.

"The North Korean nuclear and missile threat will remain a force to be reckoned with," Soo Kim told AFP.

"Given this latest progress, dealing with North Korea may be an even more formidable challenge for the Yoon administration," she added.

With its ICBM launch this week, North Korea has abandoned "self-restraint on missile tests", said Leif-Eric Easley, a professor at Ewha University in Seoul.

"The Kim regime now expects Washington to accept the intolerable or pay Pyongyang to reimpose a long-range testing freeze."