Preparations for North Korea summit moving along very well: Donald Trump

US President Donald Trump today said that preparations for the June 12 summit meeting with North Korean leader Kim Jong-un is moving along very well.

The President's statement comes a day after Singapore designated a special event area of the Sentosa island tourist resort for Tuesday's historic summit, which is expected to be covered by over 2,500 journalists from across the world.

There was initially much uncertainty over whether the summit would go ahead at all, and it was briefly called off last month by Trump after a dispute with the North Koreans over the key issue of denuclearisation.

"North Korea (summit) looks like it's moving along very well. A lot of relationship being built. A lot of negotiation going on even before the trip. But it looks like it's coming along fine," Trump said at a White House event.

Multiple US and N Korean teams are holding simultaneous meetings ahead of the Singapore Summit.

"We'll see what happens. But very important. It will be a very important couple of days," Trump said.

Japanese Prime Minister Shinzo Abe would be at the White House later this week for talks with Trump on the latter's summit meeting with North Korea.

"We certainly anticipate the summit with North Korea that will be next week to come up, as well as trade issues and other matters," White House Press Secretary Sarah sanders told reporters at her daily news conference.

At the Foggy Bottom headquarters of the State Department, Secretary of State Mike Pompeo met his Singaporean counterpart, wherein among other things they discussed the N Korean summit which is being hosted by Singapore.

Refuting media reports, State Department spokesperson Heather Nauert said the US is not paying for the North Korean delegation to stay in Singapore.

"We're not paying for their expenses," she said.

"We have had teams negotiating not only in the Demilitarised Zone every day... meetings are taking place in Singapore as well. The meetings are a little different. The ones in Singapore tend to focus more on logistics, negotiating security, protocol, all those types of things. Those meetings are ongoing," Nauert said, adding that Pompeo speaks sometimes multiple times a day with his negotiating teams.

Meanwhile, top Republican Senator Marco Rubio said that the Singapore summit is just the beginning of a process and nothing major would come out of it.

"My sense is that it will be the beginning of a process. My prediction is that at some point during this process, if I were the North Koreans, I'd want to extend this. I would imagine China is probably trying to finagle its way into it. So I think you should anticipate that at some point down the road, this will turn into a China-US-South Korea-North Korea talks," Rubio told Fox news.

To have a good deal with North Korea is going to take a little bit of time, he said.

"The important thing for us is we should not be lifting any sanctions or providing any relief until we see a clear path forward on complete and irreversible denuclearisation and getting rid of the missiles, but that may take a while. That is not going to happen in one meeting, so I think everybody needs to understand that," Rubio added.

More than 2,500 people from the local and international news media are expected to cover the event in Singapore, according to the number of registrations received by the ministry of communications and information.