Hanoi, Vietnam (CNN) President Donald Trump's Hanoi summit with Kim Jong Un , meant to demonstrate his diplomatic gamble with North Korea is working, instead ended with no joint agreement after Kim insisted all US sanctions be lifted on his country.

That was a bridge too far for the US President, who said Kim offered to take some steps toward dismantling his nuclear arsenal but not enough to warrant ending the debilitating sanctions regime on the country.

"Sometimes you have to walk," Trump said during a news conference following the conclusion of the summit, which broke up earlier than planned. "This was just one of those times."

But it was evident from early in the summit that Trump was seeking to tamp down expectations, repeating he's in no rush to strike a deal even as North Korea continues to advance its nuclear weapons program.

"I've been saying very much from the beginning that speed is not that important to me," Trump said earlier Thursday at the summit's outset. "Speed is not important to me. What is important is that we do the right deal."

Trump cast the lack of deal as only a short-term disappointment, even though he'd hoped coming into the talks to be able to point to a new, concrete pathway toward denuclearization. A major agreement struck in Hanoi may also have pushed aside embarrassing headlines about Trump's former lawyer Michael Cohen testifying the President is a racist conman.

The President, who said scheduling Cohen's testimony during his summit was a "terrible thing," instead suggested the inconclusive talks with Kim were another step in a lengthy process toward convincing the young leader to abandon his nuclear program.

And the summit ended amicably, without either man storming away.

"It was a very friendly walk," Trump said.

'Closer'

Still, the absence of a joint agreement reflects an anticlimax for a summit event Trump had hoped would prove naysayers of his diplomacy wrong.

He conceded that US and North Korean officials remain at odds about the precise definition of denuclearization, which is the ostensible goal of his efforts.

"He has a certain vision and it's not exactly our vision, but it's a lot closer than it was a year ago and I think eventually we'll get there," Trump said.

And he described Kim as singularly focused on ending the sanctions that have crippled his economy and helped bring him to the negotiating table in the first place.

Trump said Kim had offered to begin dismantling the Yongbyon nuclear facility, a step that would have amounted to a major concession. But it wasn't enough, Trump said, alluding to additional sites that comprise what is a deeply secretive nuclear program.

"We asked him to do more and he was unprepared to do that," said Secretary of State Mike Pompeo, who joined Trump on stage for the duration of the news conference. "Everyone had hoped we could do just a little bit better."

US and North Korean negotiators had been in Hanoi for days drafting language of a joint agreement ahead of the talks, and the ceremony was listed on a version of the President's public schedule released Wednesday evening. Stephen Biegun, the President's North Korea envoy, arrived several days before Trump to seal the document.

During an expanded session with aides, Trump and Kim discussed the prospect of opening a US office in Pyongyang, North Korea's capital. Kim said he would welcome the idea, and Trump deemed it a "good idea."

Yet afterward, it appeared the chances for that -- along with any other concessions or agreements -- were dashed, even as the White House insisted the talks were productive.

The two leaders departed the Metropole, the French-colonial hotel where the talks unfolded, around 1:30 p.m. local time, roughly four-and-a-half hours after the talks began.

They also left without participating in a working lunch, even as chefs had been preparing plates of foie gras and snow fish.

Lowered expectations

If the day ended without a triumphant finish, there were extraordinary moments peppered throughout the day.

In unprecedented back-and-forth exchanges with journalists, Kim insisted he was open to denuclearization, though didn't say what he believed that meant.

It's believed to be the first time Kim has answered a question from a foreign journalist, a landmark event for the iron-fisted dictator.

"If I'm not willing to do that I won't be here right now," he said through an interpreter.

Kim, for his part, also expressed cautious optimism earlier in the day that a deal would eventually be struck. But he did not suggest such an accord would come soon.

"It's too early to say," he said in response to a foreign journalist's shouted question. "From what I feel right now, I do have a feeling that good results will come out."

He again responded to journalists later in the day, albeit somewhat begrudgingly.

The two leaders went back-and-forth over the prospect of exchanging liaison officers -- a low level diplomatic partnership -- after the issue was raised by a journalist.

Initially, Kim seemed to reject the question, proposing to Trump that the media be excused from the room. But Trump seemed to goad him to answer, saying it was a good question.

"I would like to hear that answer," Trump said.

Kim responded through his interpreter, saying it would be something that was "welcome-able."

Trump expressed a similar sentiment: "I actually think it's a good idea."

Kim added it would be better for Trump and him to discuss it together in private.

Trump's dual objectives

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Trump was pursuing two objectives as he sat down once again with the North Korean dictator on Thursday: draw North Korea closer to the prospect of abandoning its nuclear weapons and regain control of the media narrative.

As he arrived at the swanky Metropole Hotel on Wednesday to advance his historic direct diplomacy with Kim, Trump was quickly upstaged by the damning congressional testimony of his longtime former attorney and adviser Michael Cohen.

By the time Trump finished dinner with Kim , the airwaves were blanketed with coverage of Cohen's testimony. A grand agreement on denuclearization might have helped in that effort to change the narrative. But on Thursday Trump repeatedly downplayed the prospects of a deal emerging from the Hanoi talks and suggested something more vague might result from his second summit with Kim.

"I can't speak for today but over a little bit longer term ... we're going to have a fantastic success," Trump said.

He described his dinner an evening earlier as positive, but did not describe in detail any of the negotiations underway.

"A lot of great ideas being thrown about," Trump said.

Cozy relationship with a brutal dictator

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The two leaders once again put their chummy personal relationship on display, walking along the flower-lined pool deck at the Metropole engaging in friendly conversation to give the cameras an opportunity to capture them in a more casual setting.

The images will only serve to fuel criticism that Trump's cozy diplomacy with Kim glosses over the rampant human rights abuses in North Korea , which include Kim's brutal assassinations of those who cross him and the imprisonment of thousands in labor camps. Trump largely avoided any mention of human rights during his talks with Kim, instead focusing on the prospects for financial investment if Kim agrees to abandon his nuclear weapons.

When a reporter asked Kim whether the topic was discussed, Trump answered for him.

"We're discussing everything," Trump said.

Later, when asked about the treatment of Otto Warmbier, an American student who spent 17 months in North Korean detention before being returned to the US in a vegetative state and subsequently dying, Trump denied Kim had been aware of the incident.

"He felt badly about it. He felt very badly," Trump said. "He tells me that he didn't know about it and I will take him at his word."

"I don't think that the top leadership knew about it," Trump added. "I don't believe that he (Kim) would have allowed that to happen."

While Trump continues to insist that there is no rush to make progress, North Korea has continued to develop its nuclear weapons program and expanded its nuclear arsenal. In just the past year, North Korea is estimated to have produced enough fissile material for an additional five to seven nuclear weapons, according to Stanford University's Center for International Security and Cooperation

That nuclear production is expected to continue so long as Trump does not secure a verifiable freeze in North Korea's nuclear production -- a US objective that so far has remained elusive.