Trump says open to meeting North Korea's Kim at DMZ

US President Donald Trump said Saturday he was open to meeting Kim Jong Un at the demilitarised zone between North and South Korea while on a trip to Seoul this week.

"After some very important meetings, including my meeting with President Xi of China, I will be leaving Japan for South Korea (with President Moon). While there, if Chairman Kim of North Korea sees this, I would meet him at the Border/DMZ just to shake his hand and say Hello(?)!," Trump tweeted from Japan's Osaka, where he is attending the G20 summit.

The surprise offer came amid a recent flurry of diplomacy over North Korea's nuclear programme after a Trump-Kim summit in Hanoi collapsed without an agreement.

After several months of public silence, an exchange of letters between the leaders appeared to have thawed the deep-freeze and raised hopes for a third summit meeting after a historic first tete-a-tete in Singapore on June 12, 2018 and the second in Hanoi in February.

Trump will be heading to Seoul immediately after the G20 summit in Osaka, where on Saturday he will hold a highly anticipated meeting with Chinese President Xi Jinping in a bid to ease trade tensions between the world's top twop economies.