United States vice president Mike Pence has raised the prospect of direct talks without preconditions between Washington and North Korea, while continuing to impose tough sanctions on the regime. His remarks follow widespread criticism of his failure to engage with a high level North Korean delegation at the opening of South Korea’s Winter Olympics at the weekend, which analysts described as a squandered opportunity. As he flew out of Seoul on Air Force Two, Mr Pence walked back from Washington’s previous hard-line stance that there would be no negotiations before Pyongyang made real concessions, telling the Washington Post that talks could start while the pressure campaign is ongoing. “The point is, no pressure comes off until they are actually doing something that the alliance believes represents a meaningful step toward denuclearisation,” he said. “So the maximum pressure is going to continue and intensify. But if you want to talk, we’ll talk,” he said. The change in policy suggests real progress was made on the sidelines of the Olympic Games, despite the overt chilliness between Mr Pence and the North’s delegation, which included Kim Jong-un’s younger sister, Kim Yo-jong. The new strategy was conceived while watching Olympic speedskating heats on Saturday evening with South Korean President Moon Jae-in, whose government is considering an invitation from Kim Jong-un to attend a rare summit in Pyongyang. The invite, which was hand-delivered by Kim Yo-jong during a lunch at the presidential palace, has revived hopes of an end to a tense international stand-off with North Korea over its nuclear and weapons programme. Ms Kim appeared to charm South Korea’s media with her near-permanent smile as she conducted a whirlwind round of diplomacy as the first member of the Kim dynasty to visit the South since the Korean War of 1950-1953. However, US Secretary of State Rex Tillerson stressed on Monday that it was still too early to judge whether the latest developments represented the start of a diplomatic process “We’ve said for some time it’s really up to the North Koreans to decide when they’re ready to engage with us in a sincere way, a meaningful way,” Mr Tillerson told reporters during a trip to Egypt. “They know what has to be on the table for conversations.” Dr Tony Michell, a North Korea expert and managing director of the Euro-Asian business consultancy, said President Moon would likely wait until after the mid-June local elections if he decided to go to Pyongyang. “He has some time and the real question is how far can he modify the American line to allow meaningful talks to take place?” he said. One negotiating option could be a “freeze for a freeze”, where North Korea would put its nuclear and missile tests on hold in exchange for the scaling down of joint US and South Korean military drills, suggested Dr Michell. However, Seoul’s regional ally Japan has urged caution. On a trip to Brunei, Taro Kono, Japan’s foreign minister, warned the world to remember that North Korea remained committed to its internationally-opposed nuclear and missile development programme. “Without being swayed by [North Korea’s] smile diplomacy, Japan will firmly coordinate with [the US and South Korea] towards the ultimate goal of denuclearising the Korean Peninsula,” he said.