Washington (CNN) A week after abruptly scrapping his prized summit with Kim Jong Un , President Donald Trump buoyantly announced on Friday the historic talks were back on for June 12 in Singapore.

His reversal came after receiving a letter from Kim, hand delivered to the White House by the dictator's top envoy . Trump initially told reporters the missive was "very interesting." But he later acknowledged he hadn't read it yet.

The contents of the note from Pyongyang appeared to matter little to Trump, who sounded an optimistic -- and conciliatory -- note about the prospects for a deal. He said harsh statements from the North lampooning Vice President Mike Pence and threatening nuclear war were a thing of the past.

"I think we're over that, totally over that, and now we're going to deal and we're going to really start a process," Trump said on the South Lawn after meeting with the North Korean envoy, Kim Yong Chol, for more than an hour in the Oval Office.

"We're meeting with the chairman on June 12 and I think it's probably going to be a very successful -- ultimately a successful process," Trump said.

The announcement capped an electric day of diplomacy at the White House, which included the highest-level meeting between a US president and a North Korean official since 2000.

'We'll see'

Trump's announcement that the summit is back on amounted to a plot twist in a reality-show back-and-forth over whether the summit would actually occur. With just over a week until the scheduled sitdown, few expect the cliffhanger aspect of the encounter will wane.

"We'll see. Remember what I say. We will see what we will see, but I think it's going to be a process that we deserve to have," Trump said.

Kim Yong Chol, a former spy chief and currently North Korea's top nuclear negotiator, arrived just after 1 p.m. ET on the South Lawn, where foreign dignitaries are typically received by the President. This time, Trump did not greet his visitor in person, leaving that task to his chief of staff John Kelly and a top CIA official.

There was little ceremony and no handshake. They walked along the Rose Garden to the Oval Office, where Kim met with Trump for more than an hour.

During their talks, Trump did not raise human rights, he said later, despite Kim's alleged involvement in the deaths of South Korean troops.

When they emerged, Trump shook Kim's hand before seeing him off in a black US government SUV. He strolled to a group of nearby reporters to declare the meeting a success.

"The relationships are building and that's a very positive thing," he said. Asked about Pyongyang's commitment to denuclearization, Trump said: "I think they want to do that. I know they want to do that."

"They want to develop as a country," Trump said.

Little to quiet skepticism

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Those assurances, however, will do little to quiet skepticism about Trump's willingness to meet Kim. It's not yet clear what steps, if any, the North has signaled it is willing to take to negotiate away its nuclear program. There are doubts Pyongyang would agree to fully relinquish its arsenal, which it's described as a survival mechanism.

Trump himself sounded conciliatory, telling reporters he was holding off applying new sanctions on North Korea and declaring he would no longer use the phrase "maximum pressure" to describe his campaign to choke off the isolated regime.

"I don't want to use the term maximum pressure anymore. I don't want to use that term," he said. "We're getting along. You see the relationship. It's not a question of maximum pressure," he said.

As Trump met with Kim Yong Chol at the White House, separate teams of US officials were making preparations for the summit in Asia. A team of negotiators were holding talks along the Korean Demilitarized Zone to draft some type of document that both leaders could agree to, and a logistics team was in Singapore arranging final details for the talks.

Trump himself was expected to participate in some briefings on the upcoming meeting at Camp David this weekend. He departed for the mountainside presidential retreat Friday afternoon with his children Donald Jr., Tiffany and Ivanka, along with Ivanka's husband Jared Kushner.

"A little relaxation, a lot of work," is how he described his weekend.

The letter

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Ahead of the meeting, top-level US officials had not read the missive from Kim to Trump, but were aware generally of its contents, a person familiar with the matter said. On Thursday the White House described the envelope as sealed.

US officials learned of the letter's substance through diplomatic channels in the absence of reading the letter itself, the person said.

The understanding among the US officials is the letter is generally positive and a step in the right direction toward a meeting between Kim and Trump. But they did not believe it contained specific commitments on the nuclear program.

"That letter was a very nice letter. Oh, would you like to see what was in that letter. How much? How much?" Trump teased reporters after his meeting.

Minutes later, he breezily acknowledged he hadn't read it.

"I haven't seen the letter yet. I purposely didn't open the letter," Trump said (by 4 p.m. ET the White House had confirmed he'd read the note).

"I didn't open it in front of the director," Trump explained on the South Lawn. "I said 'Would you want me to open it?' He said, 'You can read it later.' "

"I could be in for a big surprise, folks," he said with a smile.