US pursues direct diplomacy

The United States is quietly pursuing direct diplomacy with North Korea, a senior State Department official said on Tuesday, despite US President Donald Trump's public assertion that such talks are a waste of time.

Using the so-called "New York channel," Joseph Yun, US negotiator with North Korea, has been in contact with diplomats at Pyongyang's UN mission, the official said.

While US Secretary of State Rex Tillerson on Oct 17 said he would continue "diplomatic efforts ... until the first bomb drops," the official's comments were the clearest sign the United States was directly discussing issues beyond the release of American prisoners, despite Trump having dismissed direct talks as pointless.

There is no sign, however, that the behind-the-scenes communications have improved a relationship vexed by North Korea's nuclear and missile tests, reported Reuters.

Word of quiet engagement with Pyongyang comes despite Trump's comments, North Korea's weapons advances and suggestions by some US and South Korean officials that Yun's interactions with North Koreans had been reined in.

"It has not been limited at all, both (in) frequency and substance," said the senior State Department official.

Meanwhile, North Korea slammed Trump as "incurably mentally deranged" in a personal attack ahead of his first visit to Asia, reported AFP.

Trump, the North's state-run KCNA news agency said late Tuesday, "disclosed his true nature as a nuclear war maniac before the world and was diagnosed as 'incurably mentally deranged'".

A senior administration official announced Tuesday that President Trump would not visit the DMZ in South Korea during his tour.

And speaking to parliament yesterday, President Moon said South Korea will never tolerate North Korea as a nuclear state, nor will Seoul have nuclear weapons.

On Monday, the first two of 12 US Air Force F-35 Joint Strike Fighter jets arrived in Okinawa, where the group of stealth aircraft will begin a six-month deployment in Japan as part of Pacific Command's "theater security" program, a spokesperson for the service confirmed to CNN.

The deployment marks the first time that the Air Force's version of the F-35 has been sent to the region and is meant "to demonstrate the continuing US commitment to stability and security."