Kim Jong-un’s offer to dismantle key missile test sites represents only a “very small step forward”, analysts said, with many disappointed at the lack of progress on denuclearisation.

North Korea offered the concession during a three-day summit in Pyongyang with the South Korean president, Moon Jae-in, and also offered to close its only known nuclear complex if the United States makes its own concessions.

The two also agreed to open rail links, jointly bid for the 2032 summer Olympics and reopen cross-border tourism, and Kim said he would visit Seoul in the “near future”.

“If we look at progress in terms of speed, denuclearisation is going less than 30km/h, and inter-Korean relations are going over 100km/h,” said Nam Sung-wook, a professor of North Korean studies at Korea University.

“It’s worrying there was no mention of North Korea’s current missile and nuclear warhead stockpiles in the statement,” he added. “There’s no sign North Korea will fundamentally change its position or give anything up, it was mostly just broad and vague statements.”

Nam also said the increased exchanges between North and South Korea harmed Trump’s “maximum pressure” campaign designed to force Pyongyang to give up its nuclear weapons. US officials have been trying for months to have Kim provide a detailed list of the number of nuclear warheads and descriptions of North Korea’s nuclear infrastructure, but have reportedly been unsuccessful.

North Korea previously claimed to have shut its only known nuclear test site and has placed a moratorium on missile tests. But previous moves meant to show good faith, in particular the destruction of a cooling tower at its Yongbyon nuclear complex in 2008, have fizzled.

Donald Trump described the results of the summit as “very exciting” in a tweet. Moon will meet Trump on 25 September in New York during the United Nations general assembly. Nuclear talks between Washington and Pyongyang have stalled in recent weeks, with Trump cancelling a trip to North Korea by his top diplomat last month.

Moon’s mission during that meeting will be to “persuade Trump to meet Kim halfway and continue nuclear talks”, said Duyeon Kim, a senior fellow at the Center for a New American Security, adding the South Korean president might have a private message to convey from Kim. “Moon has the challenging task of carefully coordinating this with the denuclearisation track or else it could get dicey between the allies.”

But she warned that a joint declaration signed in Pyongyang showed Kim had not budged, and is waiting for Trump to make the first move. As Inter-Korean exchanges pick up speed, a key goal for Moon will be to sell the rapid rapprochement to his own people, with many remaining sceptical of pandering to a brutal dictator.

“Moon and Kim nailed the atmospherics of a ‘one Korean people,’ but the South Korean public writ large will keep a cautious eye on specific deliverables because they’ve seen this movie so many times before and ended up disappointed,” Duyeon Kim said.

Others framed Kim’s concessions as an effort to simply keep momentum going until he can sit down with Trump again. The White House is already planning a second summit after Kim sent Trump a “very warm, very positive” letter.

Vipin Narang, a politics professor at the Massachusetts Institute of Technology, said Kim offered “just enough to keep the charade going”.

“But at some point Kim runs out of costless concessions to milk and make ... and then what?” he wrote on Twitter.