UNITED NATIONS/WASHINGTON (Reuters) - A year after Donald Trump threatened to “totally destroy” North Korea in his first speech at the United Nations, the U.S. president will return to the podium in New York this week to tout diplomatic efforts that have reduced the risk of war.

But even if Trump’s rhetoric at the annual United Nations General Assembly is expected to differ sharply from his 2017 address in which he mocked North Korean leader Kim Jong Un as “Rocket Man” on a “suicide mission,” some U.S. officials and analysts say Pyongyang has yet to take concrete measures to show it is prepared to give up a nuclear arsenal that threatens the United States.

The change of mood was sealed when Trump and Kim met for an unprecedented summit on June 12 in Singapore, and in the past week, the North Korean leader promised South Korean President Moon Jae-in to dismantle a missile site and also a nuclear complex - if the United States takes “corresponding action.”

While appearing to set a positive tone, the commitments fell far short of Washington’s demands for a complete inventory of North Korea’s weapons programs and irreversible steps towards denuclearization.

Trump is to meet Moon on Monday to get a first-hand account of the Korean summit before delivering his U.N. address on Tuesday.

U.S. Secretary of State Mike Pompeo, meanwhile, has proposed a meeting with his North Korean counterpart, Foreign Minister Ri Yong Ho, and plans to chair a Security Council meeting on the denuclearization effort on Thursday.

Some U.S. officials are concerned Trump is taking an overly rosy view of North Korea developments.

Trump called last week’s joint declaration by Moon and Kim “very exciting” and has previously said he is willing to meet Kim a second time, in spite of a lack of obvious progress from their first meeting in Singapore.

One U.S. official, speaking on condition of anonymity, said the worry was Trump might offer Kim “too much too soon” to score a win ahead of the Nov. 6 congressional elections, which will decide whether Trump’s Republican Party maintains control of Congress.

FILE PHOTO: U.S. President Donald Trump shakes hands with North Korean leader Kim Jong Un at the Capella Hotel on Sentosa island in Singapore June 12, 2018. REUTERS/Jonathan Ernst/File Photo

POMPEO SAYS STILL WORK TO DO

While declaring the developments in the Koreas summit sufficient to allow a restart of high-level talks with North Korea, Pompeo’s tone has been more measured.

In television interviews on Friday, he said there was still work to do “to make sure conditions are right” for a second summit and reiterated that sanctions would have to remain on North Korea until it gives up its nuclear weapons.

Past U.S. insistence that North Korea act first before expecting any easing of sanctions or a formal end to the 1950-53 Korea War over have not gone down well with Pyongyang.

Pompeo’s proposed interlocutor in New York, Foreign Minister Ri, responded to Trump’s U.N. remarks last year by calling them “the sound of a dog barking” and warning that North Korea could detonate a hydrogen bomb over the Pacific.

Soon after his summit with Kim, Trump declared the North Korean nuclear threat over, despite little more than a broad pledge by Kim to “work toward” denuclearization of the Korean peninsula.

“Trump will likely continue his practice of hailing even insignificant North Korean steps as major advances,” said Evans Revere, a former U.S. negotiator with North Korea under the last Republican president, George W. Bush.

“His approach, which I have dubbed ‘strategic optimism’, seems to regard the appearance of denuclearization as more important than the real thing, since the former is easier to achieve than the latter,” he said.

Revere and other former officials and analysts said North Korea seemed to have done little more so far than repackage past promises broken in decades of failed talks.

However, Joseph Yun, who retired this year as U.S. envoy on North Korea, said relations with Pyongyang were at least “materially better” now the two sides were no longer trading threats and there was a chance to make progress.

“Are they going to completely denuclearize by January 2021?” Yun said, referring to the end of Trump’s current term that Pompeo has set for this goal.

“No. It’s going to take longer than that.”