BEIJING (REUTERS, BLOOMBERG) - China's Foreign Ministry said on Wednesday (May 23) that China has played a positive role on the Korean peninsula and hopes the planned US-North Korea summit can proceed smoothly.

Ministry spokesman Lu Kang made the comments at a regular news briefing.

US President Donald Trump reiterated on Tuesday his suggestion that North Korean leader Kim Jong Un's recent meetings with Chinese President Xi Jinping had influenced Mr Kim to harden his stance ahead of the summit.

Mr Trump had expressed pessimism about whether the summit with Mr Kim would take place, even as American officials pressed ahead with plans for a historic meeting on June 12 in Singapore.

South Korean President Moon Jae In flew to Washington for the day on Tuesday amid growing uncertainty about Mr Kim's goals for the summit after his regime made remarks critical of Mr Trump's vision of "total denuclearisation".

"There's a chance, a very substantial chance, it won't work out," Mr Trump said during an Oval Office meeting with Mr Moon. "I don't want to waste a lot of time and I'm sure he doesn't want to waste a lot of time. So there's a very substantial chance it won't work out and that's OK. That doesn't mean it won't work out over a period of time."

While the pace of diplomacy leading to the planned June summit has been fast, analysts who study Mr Kim's regime predicted that relations would get increasingly tested in the days and weeks leading up to what would be the first ever meeting between a North Korean leader and a sitting American president.

North Korea threatened to cancel the summit last week, citing remarks by US National Security Adviser John Bolton who said the regime could follow a "Libya model" of arms control.

While arms control advocates cite Libyan dictator Muammar Qaddafi's 2011 decision to give up his weapons of mass destruction programme in exchange for an easing of sanctions as a success, North Korea views his subsequent death at the hands of Nato-backed rebels as a cautionary tale.