Washington CNN  — 

President Donald Trump has actively cultivated an air of suspense around his upcoming summit with North Korean leader Kim Jong Un, but his decision last week to add another dose of reality-TV drama by teasing the release of three Americans currently being detained by the regime is raising concerns among former US diplomats.

Trump and his allies outside the government sought to fan heightened expectations surrounding the possibility of their release last week – casting the potential development as evidence of the President’s negotiating prowess ahead of a sit-down with Kim.

But experts and even some administration aides are worried the celebration may be premature and could send the wrong signals to Pyongyang or even jeopardize the prisoner’s release.

“It doesn’t take an expert to recognize that negotiations about detained US citizens can be extremely delicate,” Mintaro Oba, a former Korea desk officer at the State Department under Obama, told CNN on Monday.

“Raising expectations in public is a dangerous game, one that can signal to the other country that you now have a lot more to lose if the deal falls through,” he said.

Trump and Rudy Giuliani, a member of Trump’s legal team but not himself an employee of the government, both seemed to get out ahead of the White House and the State Department by hinting an announcement could be coming soon.

Trump tweeted about the Americans last Wednesday evening with instructions to “stay tuned.”

And Giuliani said Saturday that “there is a good chance” that three Americans detained in North Korea “will be released over the next several days,” despite saying Thursday that the release would take place that day.

An official with knowledge of the ongoing negotiations told CNN the release of the detained Americans is “imminent” following months of talks.

But inside the White House and State Department, however, officials were still working to verify reports the three Americans had been moved from labor camps to a hotel in Pyongyang. The families of the prisoners, meanwhile, said they had received no new information about their loved ones.

Some members of the administration were frustrated as reports of the American detainees’ release seemed to get ahead of official US pronouncements – fueled partly by the President’s own lawyer.

“This isn’t how we should be doing this,” sighed one US official after Giuliani’s appearance on Fox. The official said the administration had hoped any announcement about the Americans’ release would come from the President himself.

Bill Richardson, the former US energy secretary, ambassador and repeat US envoy to North Korea, told CNN on Monday that these “negotiations are best conducted quietly, privately” but while their comments were premature, Trump and Giuliani likely did not not jeopardize the release of the three Americans.

“North Korea wants to release them” but also wants to “control the message and logistics of the release,” Richardson said.

“I would urge the President and Rudy to be cautious and not say anything – let diplomacy run its course,” he added.

Joseph Yun, who until March was the administration’s top diplomat working on North Korea issues, said last week it was “worrisome” that Trump’s allies would tout a release before it’s complete.

“We really shouldn’t be talking about their release, nobody should be talking about their release, until it happens because any kind of real speculation sends the wrong signals and could jeopardize them,” said Yun, who is now a CNN global affairs analyst.

Yun traveled to Pyongyang last June to negotiate the Americans’ release, but was only successful in securing the handover of Otto Warmbier, an American student who died days after his return to the United States.

According to Oba, Trump and Giuliani may have also missed an opportunity to secure a political victory by prematurely speaking out.

“What Trump and Giuliani also doesn’t make much sense politically,” Oba said.

“Trump would have benefited a lot more if he had managed expectations until the summit, and then unveiled the release of US detainees as a “win” for himself,” he added.