SINGAPORE -- President Trump said Thursday that he's "well- prepared" to meet Kim Jong Un next week in Singapore. He also said "attitude" is more important than preparation.

CBS News correspondent Ben Tracy has already arrived in Singapore, and he says there is a buzz in the air about next Tuesday's historic summit.

It isn't clear, says Tracy, if people in the city-state are more intrigued by the prospect of catching a glimpse of President Trump, or Kim Jong Un.

The two leaders have a pretty big gap to close in their negotiations. President Trump continues to say that his goal is to get North Korea to agree to complete denuclearization, and on a quick time-line.

Kim, however, has only said he's willing to talk about it, and has made no firm promises or said what he would want in return for giving up his weapons.

On Thursday President Trump said if North Korea doesn't agree to "de-nuke," then the harsh sanctions currently in place against the regime will remain in place. He warned that if the meeting on Tuesday isn't going well, he will simply walk out of it.

But Mr. Trump continues to predict that his summit in Singapore will be a success -- and he says if he and Kim hit off, then he will invite the North Korean leader to visit the United States.

Asked Thursday what he was doing to prepare for the summit, Mr. Trump said it would largely come down to a "willingness to get things done."

"I'm very well prepared," the president, seated alongside Japanese Prime Minister Shinzo Abe, told reporters in the Oval Office. "I don't think I have to prepare very much. It's about attitude. It's about willingness to get things done. But I think I've been preparing for this summit for a long time, as has the other side. They've been preparing for a long time, also. So this isn't a question of preparation. It's a question of whether or not people want it to happen. And we'll know that very quickly."

The Trump administration has said that Secretary of State Mike Pompeo, who will be in Singapore with Mr. Trump, will travel the next day to South Korea and then on to Tokyo to brief those American allies on the historic meeting.