Once there was "fire and fury." Now there's a face-to-face summit. But experts still worry President Donald Trump is making a policy mistake. Trump's team has repeatedly criticized previous administrations for giving North Korea concessions in exchange for negotiations that never halted the state's nuclear weapons program. The Republican may now be making that same mistake, analysts warned. "Agreeing to meet without any concrete steps toward denuclearization is a major reversal of U.S. policy," said Jon Wolfsthal, former special assistant to President Barack Obama from 2014 to 2017. "Trump has previously said no meeting until North Korea takes real steps toward denuclearization — that is not where we are today." The White House did not immediately respond to a CNBC request for comment. In a phone call last month, the U.S. leader and Japanese Prime Minister Shinzo Abe agreed there would be no meaningful dialogue with Pyongyang unless ruler Kim Jong Un agreed to "complete, verifiable and irreversible denuclearization," according to a statement by Japan's foreign ministry.

The rogue state has extended a number of olive branches in recent weeks, including peace talks with Seoul and participation at the Winter Olympics. Kim also pledged to refrain from further nuclear or missile tests and understands that joint military exercises between Seoul and Washington — one of the North's major points of contention — must continue, South Korea's National Security Office head Chung Eui-yon said on Thursday. But the regime "hasn't done anything" in terms of denculearization yet, John Park, director of the Korea Working Group at Harvard Kennedy School, told CNBC on Friday. A high-profile summit between Trump and Kim at this particular juncture "just doesn't add up," he warned. Others warned that a meeting could boost the reclusive regime. "The meeting is a huge political win for Kim," said analysts at consulting firm Eurasia Group. "It essentially provides him equal status with the U.S. president and strengthens his bid to have North Korea be recognized as a de facto nuclear power."

Trump is 'being played'

Trump's "maximum pressure" policy on Kim's government in the form of tighter sanctions has won him praise among strategists, but his acceptance of Kim's invitation could change that. The isolated state has a long history of offering dialogue in exchange for concessions such as loosened sanctions or aid. Many believe May's summit could follow the same fate as the failed Six-Party talks. Trump is being "played by Pyongyang" and is "unwittingly preempting himself of the one effective non-lethal policy he has, sanctions enforcement," according to Sung-Yoon Lee, a Korean studies professor at Tufts University's Fletcher School of Law and Diplomacy.

North Korean leader Kim Jong Un attends a grand military parade celebrating the 70th founding anniversary of the Korean People's Army at the Kim Il Sung Square in Pyongyang. KCNA | Reuters

"Kim is taking a page out of his father's 2000 playbook," Yoon said. Back then, Kim Jong Il, who ruled the North from 1994 to 2011, "created a crescendo of crisis atmosphere" before "softening up the Bill Clinton administration with an invitation to visit Pyongyang," Yoon said. "Don't be surprised if Kim Yo Jong [Kim Jong Un's sister] visits Washington first as a softer reincarnation of Vice Marshal Jo Myong Rok, the highest military man next to Kim Jong Il, who visited Bill Clinton in October 2000 and lured Clinton to visit his boss in Pyongyang," Yoon said. Of course, there are other theories behind Kim's sudden interest in meeting Trump. For one, the bite of international sanctions may be forcing Pyongyang to the discussion table. The meeting could also give Kim more time to develop his nuclear weapons arsenal and enable him to more effectively seek sanctions relief, Eurasia analysts said.

The US 'isn't driving the bus at this point'

While the idea of a May summit is seen by many as an encouraging step toward peace on the Korean Peninsula — no sitting American president has ever met a North Korean leader — others are puzzled by Washington's marked change in tone. For months, the U.S. president has ramped up provocations against the reclusive regime. He's threatened to unleash "fire and fury like the world has never seen" and "totally destroy North Korea," sparking widespread fears of unilateral U.S. military strikes.