WASHINGTON — The United States hopes to one day normalize relations with North Korea, President Trump said Thursday, adding that he would invite North Korean leader Kim Jong Un to the United States if next week’s historic summit goes well.

Trump signaled that a grand bargain to reverse decades of enmity is not on the table for his unprecedented meeting Tuesday in Singapore with Kim, but sounded upbeat as he described the North Korean leader as sincere about remaking the future for his impoverished country.

‘‘We would certainly like to see normalization, yes,’’ Trump said following two hours of meetings with visiting Japanese Prime Minister Shinzo Abe.

That would come after what Trump described as a diplomatic process that could include an agreement to safeguard Kim from the threat of ouster at the hands of the United States.

‘‘I don’t think it will be one meeting,’’ Trump said.

Trump last year derided Kim as ‘‘Little Rocket Man’’ and vowed to destroy nuclear-armed North Korea if it threatened the United States or its allies, but has recently spoken about Kim more positively as he promotes the summit as a chance to strike a historic deal. On Thursday he confirmed rumors that an invitation to the White House could be in the offing for Kim, the third generation of his family to hold absolute rule in the isolated communist country sometimes called the Hermit Kingdom.

‘‘I think he would look at it very favorably, so I think that could happen,’’ Trump said.

Skeptics, including many Republicans, have worried that Trump is giving up leverage simply by meeting with Kim, since doing so implies that the North Korean leader holds equal status with the US leader.

An invitation to the White House, unthinkable only months ago, would go much further in conferring status as a global leader on a man who until this year had not left his own borders since taking office in 2011.

The Trump administration pursued tough economic sanctions against North Korea under a ‘‘maximum pressure’’ campaign designed to force Kim to bargain over his nuclear arsenal.

Trump said Thursday that he has stopped using the ‘‘maximum pressure’’ phrase because ‘‘we are going into a friendly negotiation.’’

If he starts using that phrase again after his talks in Singapore, it will be a sign that the discussion went badly, Trump told reporters, adding that a new round of tough economic sanctions against North Korea are in abeyance while the diplomacy plays out.

Earlier Thursday, Trump proclaimed himself ready for the summit, which is taking place with no precooked outcome and without the usual months or years of run-up meetings among lower level aides. The Trump administration has scheduled and planned for the session in a span of three months.

‘‘I think I’m very well prepared,’’ Trump told reporters at the start of his Oval Office meeting with Abe. ‘‘I don’t think I have to prepare very much. It’s about the attitude. It’s about willingness to get things done.’’

That willingness to make a deal is something he will assess once he sits down with Kim, Trump suggested.

‘‘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.’’

Charles Schumer, Democrat of New York, the Senate minority leader, tweeted his alarm.

‘‘With ICBMs and nuclear warheads in the hands of North Korea, the situation is far too dangerous for seat-of-the-pants negotiating,’’ Schumer wrote.

Trump has lately been playing down expectations for the summit by no longer talking about an immediate agreement to eradicate North Korea’s nuclear arsenal.

‘‘I think it’s a process,’’ Trump said. ‘‘I think it’s not a one-meeting deal. It would be wonderful if it were.’’

At the same time, Trump promised that the session will be ‘‘much more than a photo op.’’

‘‘This will be, at a minimum, we’ll start with perhaps a good relationship,’’ he said.

The summit is planned for one day, but Trump said Thursday that it remains an open question how long he’ll stay in Singapore.

‘‘I think it’s going to be a very fruitful meeting, I think it’s going to be an exciting meeting, I think we’re going to get to know a lot of people that our country never got to know,’’ he said.

Trump is seeking to get North Korea to agree to denuclearize but acknowledged that is not likely to happen immediately.

Ultimately, if North Korea does not denuclearize, ‘‘that will not be acceptable,’’ Trump said,

‘‘They have to denuke,’’ he said, adding that the United States plans to keep sanctions on North Korea in the meantime.

Abe’s main goal for the hastily scheduled meeting is to warn Trump off any quick deal with North Korea that could shortchange Japanese interests. Japan has been directly menaced by North Korean missiles fired over its waters and land, and is seen as a primary target because of its decadeslong security alliance with the United States and the presence of US forces on its soil.

Meanwhile, satellite imagery indicates that North Korea is razing some facilities used for testing one of its most dangerous missiles after Kim Jong Un announced a moratorium on nuclear and long-range missile tests, according to an analysis released this week.

A “key missile test stand’’ that was used for testing missile ejections from canisters was demolished at a test site near Kusong in North Korea’s northwest, Joseph S. Bermudez Jr., an expert on the country’s weapons systems, said in a report published Wednesday on the website 38 North.

The Kusong test site was being closely monitored by missile experts because North Korea launched its first solid-fuel midrange ballistic missile, known as Pukguksong-2, from there in February last year.

Material from The New York Times was used in this report.