NORTH Korea has warned of a nuclear war “tipping point” after condemning American bombing practice in South Korea as “a reckless provocation”.

The US and South Korea held a “live” practice session with jet bombers on a range some distance from the border with North Korea, though the aircraft flew close to the border en route to dropping the dummy bombs.

Two B-1 bombers flew 2,000 miles from Anderson Air Force Base in Guam to conduct the precision strike training exercise with South Korean fighter jets. Japanese fighter planes flew with the bombers on their way back to Guam in a united show of force.

The exercise came just days after North Korea claimed to have fired an intercontinental ballistic missile some 600 miles from its territory into the Sea of Japan.

US President Donald Trump and President Xi Jinping of China held talks at the G20 summit following the missile test, after which Trump declared “something has to be done” about North Korea’s declared aim to be a nuclear power with missiles capable of striking anywhere in the world.

However, no practical policy to deal with North Korea and its dictator Kim Jong Un was announced by either president.

The message from Pyongyang was delivered by the state-run Rodong newspaper, which accused Washington and Seoul of ratcheting up tensions with the bomber drill in an editorial titled “Don’t play with fire on a powder keg.”

The editorial column is often used to relay state government propaganda, and it was a significant increase in the rhetorical aggression.

“The US, with its dangerous military provocation, is pushing the risk of a nuclear war on the peninsula to a tipping point,” it said, describing the peninsula as the “world’s biggest tinderbox”.

The North Korean verbal attack went on to describe the joint drill as a “dangerous military gambit of warmongers who are trying to ignite the fuse of a nuclear war on the peninsula.

“A small misjudgment or error can immediately lead to the beginning of a nuclear war, which will inevitably lead to another world war.”

Even as the bombers were returning home, more details emerged of the discussions between Presidents Trump and Xi.

There will “eventually be a success” against Pyongyang, Trump said. “It may take longer than I’d like. It may take longer than you’d like. But there will be success in the end one way or the other.”

Xi told Trump that China remained “firmly committed to denuclearising the [Korean] peninsula,” according to a report from China’s state-run Xinhua news agency.

President Xi is also reported to have said that a solution on North Korea must come through dialogue and consultation involving the international community.

In a briefing to reporters, US Treasury Secretary Steven Mnuchin said the discussion was “very direct.”

He said: “I think there were substantive discussions about the financing of North Korea. We had substantive discussions about ways of dealing with North Korea together.”

There are still problems between the US and China, however. Xi had reiterated China’s strong opposition to the US deployment of its Terminal High Altitude Area Defense missile defence system in South Korea.

The US says the system is needed for defence against North Korea, but China believes it threatens its own security because its radars could be used to spy on Beijing.

Nevertheless both countries have agreed to participate in next year’s maritime military exercises, and the White House has confirmed that non-military cooperation is developing.

A statement on behalf of Trump said: “The two leaders also reviewed work in other areas in the bilateral relationship, including economic issues such as reciprocal trade and market access. President Trump and President Xi directed their security and economic teams to make progress in upcoming dialogues.”