North Korea has displayed what appears to be new long-range and submarine-based missiles on the 105th anniversary of the birth of its founding father, Kim Il Sung, as a nuclear-powered U.S. aircraft carrier group steamed towards the region.

North Korean leader Kim Jong-Un on April 15 saluted as ranks of goose-stepping soldiers followed by tanks and other military hardware paraded in Pyongyang for a show of strength with tensions mounting over his nuclear ambitions.

Amid the fanfare and regalia of its founder's birthday celebrations, North Korea rolled out what appeared to be new missiles - a brazen display as the country ratchets up its rhetoric against efforts to curb its weapons programs. He added that North Korea will keep building up its nuclear arsenal in "quality and quantity" and said Pyongyang is ready to go to war if that's what Trump wants.

The United States, its allies and China are working together on a range of responses to North Korea's latest failed ballistic missile test, Trump's national security adviser said on Sunday, citing what he called an global consensus to act.

But Choe Ryong Hae, reportedly the second-most powerful official in the country, said in a speech that Pyongyang is prepared for any threat posed by the United States.

It was unclear exactly when the conversation took place on Sunday, but Xinhua's report of the call came out after a failed missile launch by North Korea.

North Korea's ultimate goal is to have a full array of nuclear-tipped missiles in response to what Pyongyang says is hostility by Washington and Seoul meant to topple its government.

The situation in North Korea is at its most precarious in many years, and any slight miscalculation by Pyongyang could spark military conflict, Chinese analysts have said.

The Associated Press has quoted USA officials as saying the Trump administration will focus on working with China to raise pressure on North Korea rather than stepping in with military force.

Ostensibly Saturday's event was to mark the 105th anniversary of Kim Il-sung's birth - a date known as the Day of the Sun in the North - and a squadron of planes flew overhead forming the number.

In a provocative display of pageantry, North Korea boldly flexed its military might on Saturday - showing off never-before-seen intercontinental ballistic missiles and a massive hybrid rocket dubbed a "frankenmissile". As North Korea's only ally in the world, China has a large influence on North Korean actions.

"Though analysts questioned what was inside the missile shells, they said the appearance of a submarine-launched ballistic missile shows North Korea is progressing with its plan to launch missiles from anywhere in the sea".

Military experts generally agree a shooting war with North Korea would likely be far more costly than something along the lines of the recent targeted strike Trump ordered against a Syrian air base believed to be linked to a chemical weapons attack by the regime of Bashar Assad.

"And making it without prompting a furious response from Washington surely qualifies as a win to some degree from Kim's perspective", it said, referring to Kim Jong Un. "If they start a nuclear war, we will respond with nuclear strikes". During his New Year's address, Kim said the country's preparations for an ICBM launch had "reached the final stage".

The North conducted two such tests previous year alone.

So-called cold launches would also allow the missiles to be fired from silos.